So, basically, all the remaining puzzle problems become really hard or not rewarding enough. So, most developers are working on some other projects. On kangaroo readme it is mentioned 120 puzzle would take 2 months on 256 v100s to find a solution. I think 64 problem is also similarly hard. So, not much to do here unless the original puzzle maker adds more to the wallets again...

Making outgoing transactions on 70-120 wallets is also one way. But would be cleaned by people who have good experience with running kangaroo and good hardware resources... Until then no progress further. A lotta resources went in 64 and 120, so they might get cracked. After that no hopes...