posetcay: I changed the main sequence to something similar to what 1001kyu has pointed out. I also removed the hint because if opponent tries too hard to split, making local life can be better in some cases. There are 3 main sequences black can follow and it is hard to say which is better, so I marked them all correct for now.
1001kyu: Something seems wrong here. What happens after J2H2H1J3? No matter how I look at it, it's not even ko, black either lives on the bottom after capturing J2 and H1, or cuts off the group. It's even more obvious if you go J2H2H1G2F2J3
Ivan Detkov: Did you consider a possibility of connection J19 sacrificing 3 stones and leaving the group with one eye?
See my answer below. I ask other admins to take a look. The variant changes this task completely making it more complex.