A149 V2 was the next puzzle that I went back to in my backlog. I see from that I'd found the original A149 hard and hadn't tried V2 until a few days ago.
My solving path is different from both Afmob's and manu's walkthroughs. I was struggling until I found step 24 which used a "clone" although only after the two cells had been simplified. Even though it was a puzzle by manu, the cage pattern didn't look as if it would lead to a "clone" so I hadn't been looking for one.
Here is my walkthrough for A149 V2.
Prelims
a) R1C12 = {29/38/47/56}, no 1
b) R1C89 = {59/68}
c) R3C2 + R4C1 = {19/28/37/46}, no 5
d) R3C8 + R4C9 = {18/27/36/45}, no 9
e) R46C5 = {19/28/37/46}, no 5
f) R7C2 + R8C1 = {17/26/35}, no 4,8,9
g) R7C8 + R8C9 = {18/27/36/45}, no 9
h) R8C34 = {17/26/35}, no 4,8,9
i) R8C67 = {29/38/47/56}, no 1
j) 10(3) cage in N1 = {127/136/145/235}, no 8,9
k) 10(3) cage in N4 = {127/136/145/235}, no 8,9
l) 21(3) cage in N6 = {489/579/678}, no 1,2,3
m) 21(3) cage in N7 = {489/579/678}, no 1,2,3
n) 11(3) cage in N9 = {128/137/146/236/245}, no 9
o) 27(4) cage at R4C3 = {3789/4689/5679}, no 1,2
1. R1C12 = {29/38/47} (cannot be {56} which clashes with R1C89), no 5,6
2. 45 rule on R789 2 innies R7C19 = 13 = {49/58/67}, no 1,2,3
3. 45 rule on C12 1 innie R9C2 = 1 outie R7C3 + 3, R7C3 = {456}, R9C2 = {789}
3a. 21(3) cage in N7 = {489/579/678}
3b. R7C3 = {456} -> no 4,5,6 in R8C2 + R9C1
3c. Naked triple {789} in R8C2 + R9C12, locked for N7, clean-up: no 1 in R7C2 + R8C1, no 4,5,6 in R7C9 (step 2), no 1 in R8C4
[See comment after step 21.]
3d. 1 in N7 only in R89C3, locked for C3
3e. 1 in R1 only in R1C4567, CPE no 1 in R3C6
4. Killer triple 4,5,6 in R7C1, R7C3 and R7C2 + R8C1, locked for N7, clean-up: no 2,3 in R8C4
4a. 4 in N7 only in R7C13, locked for R7, clean-up: no 5 in R8C9
5. 45 rule on C89 1 outie R7C7 = 1 innie R9C8 + 1, no 1 in R7C7, no 3,8,9 in R9C8
6. 15(3) cage at R9C2 = {159/168/249/258/267/348/357} (cannot be {456} because R9C2 only contains 7,8,9)
6a. 4,5,6 only in R9C4 -> R9C4 = {456}
7. 45 rule in R9 3 innies R9C159 = 13 = {139/148/157/238/247} (cannot be {256/346} because R9C1 only contains 7,8,9), no 6
7a. R9C1 = {789} -> no 7,8,9 in R9C59
8. Hidden killer triple 7,8,9 in R9C1, R9C2 and 17(3) cage at R9C6
for R9 -> 17(3) cage at R9C6 must contain one of 7,8,9
8a. 17(3) cage at R9C6 = {269/359/368/458/467} (cannot be {179/278} which contain two of 7,8,9), no 1, clean-up: no 2 in R7C7 (step 5)
[Alternatively 17(3) cage at R9C6 cannot be {179/278} which clash with R9C12, ALS block.]
9. 10(3) cage in N1 and 10(3) cage at R4C2 cannot both be {235} (R456C2 = {235} would clash with R2C2 = {235}) -> at least one of these 10(3) cages must contain 1, CPE no 1 in R3C2, clean-up: no 9 in R4C1
[With hindsight I could have got the elimination in step 9 from simpler steps, either by simplifying the 17(3) cage at R5C1 or by using step 10, but I’ve kept step 9 as an interesting step.]
9a. 1 in N1 only in 10(3) cage = {127/136/145}
9b. 45 rule on N1 4 innies R12C3 + R3C23 = 24 = {2589/2679/3678/4569/4578} (cannot be {3489/3579} which clash with R1C12)
[I originally used a hidden killer triple in N1, 4 innies must contain one of 2,3,4, but found that wasn’t necessary.]
10. 45 rule on N4 3(1+1+1) outies R3C2 + R5C4 + R7C1 = 19
10a. Max R7C1 = 6 -> min R3C2 + R5C4 = 13, no 2,3 in R3C2, no 3 in R5C4, clean-up: no 7,8 in R4C1
11. 45 rule on N4 2(1+1) outies R5C4 + R7C1 = 1 innie R4C1 + 9, IOU no 9 in R5C4
11a. 9 in 27(4) cage at R4C3 only in R456C3, locked for C3 and N4
11b. Max R5C4 + R7C1 = 14 -> no 6 in R4C1, clean-up: no 4 in R3C2
12. 17(3) cage at R5C1 = {368/458/467} (cannot be {278} because R7C1 only contains 4,5,6), no 1,2
12a. Min R7C9 = 7 -> max R56C9 = 6, no 6,7,8,9 in R56C9
13. 45 rule on N6 2(1+1) outies R5C6 + R7C9 = 1 innie R4C9 + 6, IOU no 6 in R5C6
13a. Min R5C6 + R7C9 = 8 -> min R4C9 = 2, clean-up: no 8 in R3C8
13b. Max R4C9 = 8 -> max R5C6 + R7C9 = 14 -> max R5C6 = 7
14. R12C3 + R3C23 (step 9b) = {2589/2679/3678/4578} (cannot be {4569} which clashes with R7C3)
14a. 10(3) cage in N1 (step 9a) = {136/145} (cannot be {127} which clashes with R12C3 + R3C23), no 2,7
15. Hidden killer triple 7,8,9 in R1C1, 17(3) cage at R5C1 and R9C1 for C1, 17(3) cage at R5C1 contains one of 7,8, R9C1 = {789} -> R1C1 = {789}, clean-up: no 7,8,9 in R1C2
16. 11(3) cage in N9 = {128/137/146/236/245}
16a. 5 of {245} must be in R7C7 -> no 5 in R8C8 + R9C9
16b. 8 of {128} must be in R7C7 -> no 8 in R8C8
17. 2 in C1 only in R48C1 -> no 7 in 10(3) cage at R4C2
17a. R4C1 = 2 => R3C2 = 8 => naked triple {789} in R389C2, locked for C2
R8C1 = 2 => R7C2 = 6 => naked quad {6789} in R3C789C2, locked for C2
[I got the idea for this step having just completed Human Solvable 7.]
17b. -> 10(3) cage at R4C2 = {136/145/235}
17c. Hidden killer pair 1,2 in R4C1 and 10(3) cage at R4C2
for N4 -> R4C1 = {12}, clean-up: R3C2 = {89}
17d. 7 in C2 only in R89C2, locked for N7
18. R5C4 + R7C1 = R4C1 + 9 (step 11)
18a. Max R4C1 = 2 -> max R5C4 + R7C1 = 11, max R5C4 = 7
19. R9C159 (step 7) = {139/148/238}, no 5
19a. 15(3) cage at R9C2 (step 6) = {159/258/267/357} (cannot be {168/249/348} which clash with R9C159), no 4
20. 45 rule on N47 3 outies R589C4 = 1 innie R4C1 + 16
20a. R4C1 = {12} -> R589C4 = 17,18 = {467/567}, 6,7 locked for C4
21. R7C7 + R8C8 + R9C9 = 11, R7C7 = R9C8 + 1 (step 5) -> R8C8 + R9C89 = 10 = {127/136/145/235}
21a. 5,6 of {136/145} must be in R9C8 -> no 6 in R8C8, no 4 in R9C8, clean-up: no 5 in R7C7 (step 5)
[It was only when I looked at my posted A149 walkthrough, after I’d finished this puzzle without looking at that earlier walkthrough, that I realised that step 21 was actually 45 rule on C89 3 innies R8C8 + R9C89 = 10. The same applies for step 3c which is more directly 45 rule on C12 3 innies R8C2 + R9C12 = 24.
I also missed these innies when I solved A149.]
22. 17(3) cage at R9C6 (step 8a) = {269/359/458/467} (cannot be {368} which clashes with R9C159)
22a. 5 of {359/458} must be in R9C8 -> no 5 in R9C67
23. 1 in N8 only in 22(5) cage = {12379/12469/12478/13459/13468} (cannot be {12568/13567} which clash with R9C4)
23a. Killer triple 5,6,7 in 22(5) cage, R8C4 and R9C4, locked for N8, clean-up: no 4,5,6 in R8C7
24. R3C2 + R89C2 = {89} + {789}, R89C2 + R9C1 = {789} + {89} -> R3C2 = R9C1
[That had been there since step 17c but I’ve only just spotted how to use it.]
24a. R4C1 + R3C2 = [19/28] -> R49C1 = [19/28] = 10
24b. 45 rule on C1 4 remaining innies R1238C1 = 18 = {1359/2367/2457} (cannot be {1269/1278} which clash with R4C1, cannot be {1368/1458/2349} which clash with R49C1, cannot be {1467/3456} which clash with 17(3) cage at R5C1, cannot be {2358} which clashes with combinations for 10(3) cage in N1), no 8, clean-up: no 3 in R1C2
24c. 2 of {2367} must be in R8C1 -> no 6 in R8C1, clean-up: no 2 in R7C2
24d. R23C1 = {13/15/36/45} -> R2C2 = {146}
25. 6 in N7 only in R7C123, locked for R7, clean-up: no 3 in R8C9
[While checking I found that I’d missed a couple of clean-ups for R9C8 and later missed a placement for R9C8 after fixing R7C7. I’ve left them out rather than re-working later steps.]
26. 11(3) cage in N9 = {128/137}, no 4, 1 locked for N9, clean-up: no 8 in R7C8 + R8C9
26a. R7C8 + R8C9 = [36/54] (cannot be {27} which clashes with 11(3) cage), no 2,7
27. Naked quad {3456} in R7C1238, locked for R7
27a. 11(3) cage in N9 (step 26) = {128/137}
27b. R7C7 = {78} -> no 7 in R8C8
27c. 1,2 in R7 only in R7C456, locked for N8, clean-up: no 9 in R8C7
28. R9C159 (step 19) = {139/148/238}
28a. 1,2 only in R9C9 -> R9C9 = {12}
29. 13(3) cage at R5C9 = {139/148/157/238/247} (cannot be {256/346} because R7C9 only contains 7,8,9)
, no 629a. Killer pair 1,2 in R56C9 and R9C9, locked for C9, clean-up: no 7 in R3C8
30. 9 in N9 only in R7C9 + R9C7
30a. 45 rule on N9 4 innies R7C9 + R8C7 + R9C78 = 25 = {2689/3679/4579} (cannot be {3589} which clashes with R7C8)
30b. 45 rule on N9 2 innies R7C9 + R8C7 = 1 outie R9C6 + 8
30c. R9C6 = {3489} -> R7C9 + R8C7 = 11,12,16,17 = [92/93/97/98] (cannot be [83] which clashes with the 11(3) cage) -> R7C9 = 9, R7C1 = 4 (step 2), clean-up: no 5 in R1C8
[I originally did this step using interactions between the combinations for R7C9 + R8C7 + R9C78 and the permutations for R9C78 in 17(3) cage at R9C6. Then I realised that using the second 45 rule on N9 was much simpler.]
31. R7C9 = 9 -> R56C9 (step 29) = {13}, locked for C9 and N6 -> R9C9 = 2, clean-up: no 6 in R3C8, no 9 in R8C6
31a. R8C8 = 1 (hidden single in N9), R7C7 = 8 (step 26), clean-up: no 8 in R4C9, no 7 in R8C4, no 3 in R8C6
31b. R9C3 = 1 (hidden single in N7)
32. 21(3) cage in N7 = {579/678} -> R8C2 = 7, R8C7 = 3, R8C6 = 8, R7C8 = 5, R8C3 = 2, R8C1 = 5, R8C4 = 6, R8C9 = 4, R8C5 = 9, R7C3 = 6, R9C1 = 8, R7C2 = 3, R9C24 = [95], R3C2 = 8, R4C1 = 2, clean-up: no 1 in R4C5, no 1,8 in R6C5
33. R7C1 = 4 -> R56C1 = 13 = {67} (only remaining combination), locked for C1 and N4 -> R1C1 = 9, R1C2 = 2, clean-up: no 5 in R1C9
33a. Naked triple {145} in R456C2, locked for C2 and N4 -> R2C2 = 6
33b. Naked triple {389} in R456C3, locked for C3, R5C4 = 7 (cage sum), R56C1 = [67], clean-up: no 3 in R46C5
33c. Naked triple {457} in R123C3, CPE no 4 in R3C4
34. R9C78 = {67} = 13 -> R9C6 = 4, R9C5 = 3
35. Naked pair {68} in R1C89, locked for R1 and N3
35a. Naked pair {57} in R23C9, locked for C9 and N3 -> R4C9 = 6, R3C8 = 3, R23C1 = [31], R1C89 = [68], R9C78 = [67], clean-up: no 4 in R6C5
36. Naked triple {489} in R456C8, locked for C8 and N6 -> R2C8 = 2
37. Naked pair {25} in R56C7, locked for C7 and 17(4) cage at R4C7 -> R4C7 = 7, R5C6 = 3 (cage sum), R56C9 = [13]
37a. R4C3 = 3 (hidden single in N4)
38. 36(7) cage at R3C3 = {1245789} -> R3C3 = 7, R23C9 = [75]
39. R6C5 = 6 (hidden single in N5), R4C5 = 4, R3C5 = 2, R3C4 = 9, R3C6 = 6, R3C7 = 4, R12C7 = [19], R1C6 = 5 (cage sum)
and the rest is naked singles.