Sums are for heights of skyscrapers visible from the edges. Only those higher than the previous one(s) count toward the sums.
On the odd-numbered rows and columns, which are normal ones containing 1-9, each sum must include 9, the height of the highest skyscraper, which can be seen from each edge. However this doesn’t necessarily apply for the even-numbered rows and columns where repeated numbers are allowed; for these rows and columns the height of the highest skyscraper may be less than 9.
Since this an ORC puzzle, I’ve stated placements in odd rows/columns.
This is a KiMo, with the totals being xy where it has been specified that x is never 0, y never 7.
There are two three-in-a-rows and two four-in-a-rows, which are required to give a unique solution. Since it is not specified otherwise, these repetitions may possibly be in the same row/column.
It has been specified that all totals in the even-numbered rows and columns must contain at least one of 7,8,9; I originally started without that specification, but have re-worked after step 1 to take account of it.
1a. Skyscrapers starting with 8 or 9 must total 8 (possible for even rows/columns), 9 or 17. Since no totals are given as 17 and xy cannot be 8, 9 or 17, rows/columns starting/finishing with 8,9 must be ones with unspecified totals.
1b. Unspecified upper totals only in C3 and C8, right-hand total 12 in R1 must contain 9 = [93] -> R1C89 = [93], R1C3 = 8, all placed for R1, 8 placed for C3, 3 placed for C9, no 7 in R1C24, no 7,8,9 in R2C24, no 7,9 in R2C3, no 8,9 in R2C7, no 2,3,4,8 in R2C8, no 2,4,8,9 in R2C9 (AK, FNC, NC)
1c. Unspecified right-hand totals only in R3 and R5, upper total 19 in C9 with R1C9 = 3 cannot contain 8 -> R3C9 = 9, R5C9 = 8, both placed for C9, 9 placed for R3, 8 placed for R5, no 9 in R2C8, no 8 in R3C8, no 7,8,9 in R46C8, no 7 in R46C9, no 7,9 in R5C8 (AK, FNC, NC)
1d. Upper total in C9 = 19, R13C9 = [39] = 12 -> R2C9 = 7 (cage sum), placed for C9, no 6 in R2C8, no 6,7 in R3C8 (AK, FNC, NC)
1e. Unspecified left-hand totals only in R2 and R6, cannot make upper total in C1 = 18 with 9 in R2C1 -> R2C1 = 8, R6C1 = 9, both placed for C1, no 7 in R13C1, no 7,8 in R3C2, no 9 in R5C2, no 8 in R6C2, no 8,9 in R7C2 (AK, FNC, NC)
1f. Upper total in C1 = 18, R26C1 = [89] = 17 -> R1C1 = 1 (cage sum), placed for R1 and C1, no 2 in R1C2, no 1,2 in R2C2 (AK, FNC, NC)
1g. R1C2 = {456} -> no 5 in R2C3 (AK, FNC)
1h. Unspecified lower totals only in C4 and C8, left-hand total in R9 = 15 must contain 9 = [249/69] -> R9C1 = {26}, R9C4 = 9, R9C8 = 8, both placed for R9, no 9 in R8C3, no 8 in R8C4, no 8,9 in R8C5, no 7,8,9 in R8C7, no 7,9 in R8C8, no 7 in R9C7 (AK, FNC, NC)
1i. Left-hand total in R9 = 15 = [249/69] cannot contain 7 -> no 7 in R9C23, also no 5,6 in R9C2, no 6 in R9C3 (NC)
1j. 7 in R1 only in R1C567 -> no 6 in R1C6, no 6,8 in R2C6 (FNC, NC)
1k. 7 in R9 only in R9C56 -> no 6,7 in R8C5, no 6,8 in R8C6, no 6 in R9C56 (AK, FNC, NC)
1l. Right-hand total in R9 = xy must be at least 10, R9C8 = 8 -> no 1 in R9C9
2a. C2 must contain at least one of 7,8,9, lower total in C2 = 10 = [713/73/82/91] with possible repeats (cannot be [721] because of NC) -> R9C2 = {123}, no 2 in R89C13 (AK, FNC, NC)
2b. R9C1 = 6, placed for R9 and C1, no 5,7 in R8C1, no 5,6,7 in R8C2 (AK, FNC, NC)
2c. R8C1 = {34} -> no 3,4 in R7C12, no 3 in R9C2 (AK, FNC, NC)
2d. R9C2 = {12} -> no 1 in R89C3 (AK, FNC, NC)
2e. R9C3 = {345} -> no 4 in R8C234 (AK, FNC)
3a. Upper total in C5 = 19 must contain 9 -> total of remaining visible cells = 10 = [28/46] (cannot be [235] or [2135] because of NC) -> R1C5 = {24}
3b. R1C5 = {24} -> no 3 in R2C456 (FNC, NC)
3c. Remaining visible cells = [28/46] -> R2C5 = {1268}
3d. Either R2C5 is an invisible cell or R2C5 = {68} -> no 7 in R3C5 (NC)
3e. 7 in R1 only in R1C67 -> no 6 in R1C7, no 6,7 in R2C7 (AK, NC)
3f. 6 in R1 only in R1C24 -> no 6 in R2C3 (AK)
4a. Left-hand total in R3 = 30 must contain both of 8,9 since 9 is in R3C9 -> remaining visible cells must total 13 = [247/256/346] -> R3C1 = {23}, no 3 in R2C2, no 2,3 in R3C2 + R4C12 (AK, FNC, NC)
4b. The second visible digit must be 4 or 5 -> no 6 in R3C2, also no 6 in R3C3 because [247] can only have 6 after 7 while [256/346] must include one hidden cell because of NC
4c. 6 of [256/346] cannot be further left that R3C4 while 7 of [247] cannot be further left than R3C3 -> no 8 in R3C4 (NC)
4d. 2 of [247/256] must be in R3C1, [346] must start [31] -> no 2 in R3C3 (NC)
4e. 8 in R3 only in R3C567 -> no 7,9 in R24C6, no 7 in R3C6 (AK, FNC, NC)
4f. R2C2 = {456} -> no 5 in R3C3 (AK, FNC)
4g. R45C1 cannot both be {45} (NC) -> R78C1 must contain one of 4,5 -> no 5 in R7C2 (NC)
5a. Left-hand total in R4 = 16, R4C1 = {457} -> only possible remaining visible permutations are [457/79] -> R4C1 = {47}
5b. [457/79] -> no 6,8 in R4C2 (NC)
5c. 5 in C1 only in R57C1 -> no 4,5,6 in R6C2 (AK,FNC)
5d. Lower total in C2 (step 2a) = [82/91], may possibly contain 1 in hidden cells or R89C2 = [82] (only remaining 8 in C2) -> no 2,3 in R8C2
6a. Remaining visible cells at left-hand end of R3 (step 4a) = [247/256/346] -> R3C12 = [24/25/31] -> no 4 in R4C1 (AK, FNC, NC)
6b. R4C1 = 7, placed for C1, no 6,7 in R5C2 (AK, FNC)
6c. R3578C1 = [2453/3524] -> R5C1 = {45}, no 4,5 in R45C2 (NC)
6d. R5C2 = {123} -> no 2 in R456C3 (AK, FNC, NC)
6e. Consider placements for R3C1 = {23}
R3C1 = 2, placed for C1
or R3C1 = 3, R3C2 = 1 => no 2 in R2C3 (FNC) => R7C3 = 2 (hidden single in C3)
-> R7C1 = 5, R358C1 = [243], 2 placed for R3, 4 placed for R5, 5 placed for R7, no 1 in R34C2, no 3 in R56C2, no 2,6 in R7C2, no 2 in R9C2 (FNC, NC)
6f. R9C2 = 1, placed for R9, no 8 in R8C2 (step 5d)
6g. R3C2 = {45} -> no 4 in R23C3, no 4,5 in R4C3 (AK, FNC, NC)
6h. R2C3 = {123} -> no 2 in R1C4 (AK, FNC)
6i. 2 in R1 only in R1C567 -> no 1 in R2C6 (FNC, NC)
6j. R5C2 = {12} -> no 1 in R456C3 (AK, FNC, NC)
7a. Consider placements for 2 in C3
R2C3 = 2 => no 1,3 in R3C3 (NC) => R3C3 = 7
or R7C3 = 2 => no 1 in R7C2, no 3 in R68C3 (NC), R7C2 = 7 => no 6,7 in R8C3 (AK, FNC), R8C3 = 5 => no 4 in R9C3 (NC), R9C3 = 3, R23C3 = [17]
-> R3C3 = 7, placed for R3 and C3
7b. R3C3 = 7 -> no 6 in R2C24 + R3C4 + R4C3, no 7 in R4C2, no 6,7,8 in R4C4 (AK, FNC, NC)
7c. R4C2 = 9 -> no 9 in R5C3 (AK)
7d. Right-hand total in R4 = 15 must contain 9 so no 7,8 visible, 9 repeated can be as far right at R4C7 -> no 7,8 in R4C7, no 8 in R4C6 (NC)
7e. R27C3 = {12} (hidden pair in C3) -> no 1 in R3C4 + R78C2, no 1,2 in R6C2 + R678C4 (AK, FNC, NC)
7f. R7C2 = 7, placed for R7, no 6 in R68C3 (FNC)
7g. R8C3 = {35} -> no 4 in R9C3 (NC)
7h. Naked pair {35} in R89C3, locked for C3, R456C3 = [964], 6 placed for R5, no 5 in R4C4, no 3,5,7,9 in R5C4, no 7 in R6C2, no 3,5,6,7 in R6C4, no 3,4 in R7C4 (AK, FNC, NC)
7i. Naked pair {12} in R5C24, locked for R5
7j. R5C4 = {12} -> no 1,2 in R46C5 (AK, FNC)
7k. R5C8 = {35} -> no 4 in R46C789 (AK, FNC, NC)
7l. R3C13 = [27] -> R3C2 (step 6a) = 4, placed for R3, no 5 in R2C2 (NC)
7m. R2C2 = 4 -> no 5 in R1C2 (NC)
7n. R3C4 = {35} -> no 4 in R2C4 + R4C45 (FNC, NC)
7o. 7 in R5 only in R5C567 -> no 6 in R4C6, no 6,8 in R6C6 (AK, FNC, NC)
8a. Right-hand total in R4 = 15 must contain 9 -> visible cells = [942/951/96], no 5 in R4C9
8b. 4 in C9 only in R789C9 -> no 3,5 in R8C8, no 5 in R8C9 (FNC, NC)
8c. Consider placements for 5 in C9
R6C9 = 5 => no 4,6 in R7C9
or R9C9 = 5 => no 4,6 in R8C9
-> at least one of R78C9 must be {12} but cannot both be {12} (NC) -> R4C9 = {12}
8d. Right-hand total in R4 = 15, no 4 in R4C8 -> visible cells = [951], 1 placed for C9, no 1 in R3C8, no 6 in R4C7, no 2,3,6 in R4C8 (AK, FNC, NC)
8e. R3C8 = {35} -> no 4 in R2C7 (FNC)
8f. Lower total in C9 = 28 must contain 8,9 -> remaining total = 11 = [56] (cannot be [245] because cannot then place 6 in C9, NC) -> R9C9 = 5, placed for R9 and C9, R89C3 = [53], 3 placed for R9, no 6 in R7C4, no 3,6 in R8C4, no 4,6 in R8C9 (FNC, NC)
8g. R8C9 = 2, placed for C9 -> R67C9 = [64], 4 placed for R7, no 5 in R5C8, no 3,5 in R6C8, no 1,2,3,6 in R7C8, no 1,4,6 in R8C8 (AK, FNC, NC)
8h. R5C8 = 3, placed for R5, no 2,3 in R46C7, no 2 in R6C8 (AK, FNC, NC)
8i. R9C7 = {24} -> no 3 in R8C67 (NC)
8j. R9C567 = {247} -> no 1,5 in R8C6 (AK, FNC, NC)
9a. Consider placement for R1C2 = {46}
R1C2 = 4
or R1C2 = 6 => R1C4 = {45}, no 4 in R1C5 (NC)
-> R1C5 = 2, placed for R1 and C5
9b. Upper total in C5 = 19 must contain 9 -> total of remaining visible cells = 10 (step 3a) = [28] -> R2C5 = 8, placed for C5, no 7 in R1C6, no 8 in R3C6 (AK, FNC)
9c. R1C5 = 2 -> no 2 in R2C46 (AK)
9d. R1C7 = 7 (hidden single in R1), placed for C7, no 7 in R2C8 (AK)
9e. R3C7 = 8 (hidden single in R3), placed for C7
9f. R1C6 = {45} -> no 5 in R2C7 (AK, FNC)
9g. 2 in R9 only in R9C67 -> no 1,2 in R8C7 (AK, FNC, NC)
9h. 4 in C7 only in R89C7 -> no 4 in R9C6 (AK)
9i. 6 in C7 only in R678C7 -> no 6 in R7C6 (AK)
10a. R3C56 = {16} (hidden pair in R3) -> no 5 in R2C6 (FNC, NC)
10b. R2C6 = 4 -> no 5 in R1C6, no 3 in R2C7 (NC)
10c. R1C6 = 4, placed for R1 -> R1C24 = [65]
10d. R7C7 = 3 (hidden single in C7), placed for R7, no 2,3,4 in R6C6, no 2 in R7C6, no 2,4 in R8C6, no 4 in R8C7, no 2 in R8C8 (AK, FNC, NC)
10e. R9C7 = 4 (hidden single in C7), placed for R9 -> R9C56 = [72], 7 placed for C5, R5C6 = 7 (hidden single in R5), no 6 in R4C5 + R6C57, no 7 in R8C46, no 1,3 in R8C5, no 5 in R8C7 (AK, FNC, NC)
10f. Naked pair {59} in R5C57 -> no 5 in R4C6, no 5,9 in R6C6 (AK)
10g. R2C7 = 2 (hidden single in C7), no 1 in R2C8 + R3C6, no 3 in R3C8 (FNC, NC)
10h. R3C68 = [65], placed for R3, R3C5 = 1, placed for C5, no 1 in R2C4, no 1,2 in R4C46, no 5 in R4C57 (AK, FNC)
10i. R7C5 = 6 (hidden single in R7 and C5), no 7 in R6C6, no 5 in R8C45 (FNC, NC)
10j. 3 in C5 only in R46C5 -> no 2 in R5C4 (FNC)
10k. R5C4 = 1, placed for R5
[And now to apply the final condition, 4 in a row twice and 3 in a row twice.]
11a. 4 in a row is only possible in R4 and C4 -> R4C2345 = [9999], R6789C4 = [9999], 9 placed for R7 and C5 -> R5C5 = 5, placed for R5 and C5, R5C7 = 9, placed for C7, R68C5 = [34], R7C368 = [218], R2C3 = 1, no 4 in R4C6 (FNC)
11b. R7C6 = 1 -> no 1 in R6C7 (AK)
11c. R6C7 = 5 -> no 6 in R6C8 (NC)
11d. Right-hand total in R4 = 15, visible cells must be [951] -> R4C8 = 5 (alternatively R234C8 are the second 3 in a row)
Now we are down to naked singles.
I've checked through my WT several times making detail changes. I hope I've now got it right; if you spot any errors, particularly in the AK/FNC/NC eliminations, please send me a PM.