There are disjoint cages R1C13, R1C7+R3C9, R7C1+R9C3 and R79C9
Prelims
a) R1C13 = {18/27/36/45}, no 9
b) R1C7+R3C9 = {18/27/36/45}, no 9
c) R2C3 + R3C2 = {49/58/67}, no 1,2,3
d) R3C45 = {59/68}
e) R4C2 + R5C3 = {29/38/47/56}, no 1
f) R5C4 + R6C5 = {29/38/47/56}, no 1
g) R5C5 + R6C4 = {17/26/35}, no 4,8,9
h) R5C78 = {19/28/37/46}, no 5
i) R7C1 + R9C3 = {29/38/47/56}, no 1
j) R7C5 + R8C6 = {29/38/47/56}, no 1
k) R7C8 + R8C7 = {16/25/34}, no 7,8,9
l) R79C9 = {29/38/47/56}, no 1
m) R8C1 + R9C2 = {17/26/35}, no 4,8,9
n) R8C2 + R9C1 = {59/68}
o) 10(3) cage at R3C1 = {127/136/145/235}, no 8,9
1a. 45 rule on N2 1 innie R3C6 = 2, clean-up: no 7 in R1C7, no 9 in R7C5
1b. 45 rule on N3 1 innie R3C7 = 4 -> R4C7 = 6 (cage sum), clean-up: no 5 in R1C7, no 9 in R2C3, no 3,5 in R3C9, no 5 in R5C3, no 4 in R5C8, no 1,3 in R7C8
1c. 45 rule on N14 1 outie R4C4 = 4, clean-up: no 7 in R5C34 + R6C5
1d. 45 rule on N5 1 remaining innie R6C6 = 6, clean-up: no 5 in R5C4 + R6C5, no 2 in R5C5 + R6C4, no 5 in R7C5
1e. 45 rule on N1 2 innies R3C13 = 8 = {17/35}
1f. 45 rule on N9 2 innies R7C79 = 12 = {39/57}
1g. R6C6 = 6 -> R7C67 = 10 = [19/37/73], clean-up: no 7 in R9C7
1h. R4C4 = 4 -> R34C3 = 12 = [39/57/75], clean-up: no 7 in R3C1
1i. R7C1 + R9C3 = {29/38/47} (cannot be {56} which clashes with R8C2 + R9C1)
2. Hidden killer triple 1,2,3 in R1C13, 15(3) cage at R1C2 and R3C13 for N1, R3C13 contains one of 1,3, 15(3) cage cannot contain more than one of 1,2,3 -> R1C13 and 15(3) cage must each contain one of 1,2,3 -> R1C13 = {18/27/36}, no 4,5
2a. Combined cages R1C13 + R3C13 = {18}{35}/{27}{35}/{36}{17}, 3 locked for N1
3. 45 rule on R6789 3 outies R5C245 = 15
3a. R5C45 cannot total 8 which clashes with R5C5 + R6C4, CCC -> no 7 in R5C2
3b. R5C45 cannot total 11 which clashes with R5C4 + R6C5, CCC -> no 4 in R5C2
4. 45 rule on R12 3 outies R3C289 = 17 = {179/368} (cannot be {359} because R3C9 only contains 1,6,7,8), no 5, clean-up: no 8 in R2C3
4a. R3C289 = {179/368}, 3 of {368} only in R3C8 -> no 6,8 in R3C8
4b. R3C89 cannot total 9 which clashes with R1C7 + R3C9, CCC -> no 8 in R3C2, clean-up: no 5 in R2C3
4c. 6 of {368} must be in R3C2 -> no 6 in R3C9, clean-up: no 3 in R1C7
4d. 9 of {179} must be in R3C2 (cannot be [791] because then no possible combination for 15(3) cage at R2C7), no 7 in R3C2, no 9 in R3C8, clean-up: no 6 in R2C3
[I can see a way to further reduce R3C289 but it’s above the SS score level, so I’ll leave it for now.]
5. 15(3) cage at R2C7 = {159/168/267/357} (cannot be {258} which clashes with R1C7 + R3C9)
5a. 6 of {168/267} must be in R2C8 -> no 2,8 in R2C8
5b. Killer pair 1,7 in R1C7 + R3C9 and 15(3) cage, locked for N3
6. 16(3) cage at R4C5 = {178/259/358}
6a. 2 of {259} must be in R4C5 -> no 9 in R4C5
[Just spotted another way to do it, which only works after I retrospectively added step 4d.]
7. R2C3 + R3C2 = [49/76], R3C13 = [17]/{35} -> combined cage R2C3 + R3C2 + R3C13 = [49]{35}/[76]{35} (cannot be [4917] which clashes with R3C289 = 9{17}, overlapping cages) -> R3C13 = {35}, locked for R3 and N1, clean-up: no 6 in R1C13, no 9 in R3C45, no 5 in R4C3 (step 1h)
7a. Naked pair {68} in R3C45, locked for R3 and N2 -> R3C2 = 9, R2C3 = 4, clean-up: no 1 in R1C7, no 7 in R4C2, no 2 in R5C3, no 7 in R7C1, no 5 in R9C1
7b. Naked pair {17} in R3C89, locked for N3
7c. 4 in N2 only in 14(3) cage at R1C5 = {149/347}, no 5
7d. 10(3) cage at R3C1 = {136/145/235} (cannot be {127} because R3C1 only contains 3,5), no 7
7e. 4,6 of {136/145} only in R5C1 -> no 1 in R5C1
7f. Killer pair 2,8 in R1C13 and R1C7, locked for R1
7g. 17(3) cage at R1C8 = {269/359/368}
7h. 2,8 of {269/368} must be in R2C9 -> no 6 in R2C9
8. R34C3 (step 1h) = [39] (cannot be [57] because cannot then place 7 in N7), clean-up: no 2,8 in R4C2 + R7C1
8a. R3C1 = 5 -> R45C1 = 5 = [14/23/32], no 6, clean-up: no 2 in R9C2
8b. 7 in N4 only in R6C123, locked for R6, clean-up: no 1 in R5C5
9. 6 in R5 only in R5C2 or R5C3 + R4C2 = [65] -> no 5 in R5C2
9a. 45 rule on R6 2 innies R6C45 = 1 outie R5C2 + 4
9b. R6C45 cannot total 6 -> no 2 in R5C2
9c. R6C45 cannot total 7 (because R5C25 cannot both be 3) -> no 3 in R5C2
9d. R5C2 = {168} -> R6C45 = 5, 10, 12 = [32/19/39], clean-up: no 3,8 in R5C4, no 3 in R5C5
9e. Naked pair {29} in R5C4 + R6C5, locked for N5
[Cracked. The rest is fairly straightforward; some clean-ups omitted in step 10.]
10. 13(3) cage at R7C2 = {148/157/238/247} (cannot be {256} which clashes with R8C2 + R9C1, cannot be {346} because 3,4 only in R7C2), no 6
10a. 3,4 on {238/247} must be in R7C2 -> no 2 in R7C2
10b. R5C3 = 6 (hidden single in C3) -> R4C2 = 5, clean-up: no 9 in R9C1
10c. R7C1 = 9 (hidden single in N7) -> R9C3 = 2, clean-up: no 7 in R1C1, no 1 in R7C6, no 3 in R9C7 (step 1f)
10d. Naked pair {68} in R8C2 + R9C1, locked for N7, clean-up: no 1 in R8C1 + R9C2
10e. Naked pair {34} in R8C1 + R9C2, locked for N7
10f. Naked pair {37} in R7C67, locked for R7 -> R7C23 = [15], R8C3 = 7, R5C2 = 8, R8C2 = 6, R9C1 = 8, R12C2 = [72] -> R2C1 = 6 (cage sum)
10g. R5C2 = 8, R6C3 = 1 -> R6C12 = 11 = [74]
10h. R6C4 = 3 -> R5C5 = 5
10i. 16(3) cage at R4C5 = {178}, 8 locked for R4
10j. R5C9 = 4 (hidden single in N6) -> R4C89 = 10 = {37}, locked for R4 and N6
10k. R5C78 = {19}, locked for R5 and N6, R5C6 = 7, R7C67 = [37] -> R9C7 = 5 (step 1f) -> R9C56 = 11 = [74], R9C2 = 3
10l. R1C1 = 1, R12C6 = [91], R4C6 = 8, R8C5 = 5 -> R7C5 = 6
10m. And after clean-ups: R79C9 = [29]
and the rest is naked singles.