When I start a launcher with both Serene Seasons and More Culling, it keeps crashing.

After disabling either, it seems to stop. I saw that there was an Issue opened from February that mentioned this issue here and claimed they also reported it to the Serene Seasons devs. However, even though the issue has been closed it still persists, despite someone complaining also in October about the same issue on the same thread.

Is the problem solved, and I am unaware, or has it been ignored?

backport isn't planned. sorry

the issue was fixed in 0.25.0-beta.1

But 0.25.0-beta.1 seems to be for 1.20.5 and not 1.20.1? I have tested it by adding it to my mod pack, it says it's completely incompatible with 1.20.1.

Am I misunderstanding something?

I have also looked at Serene Season's side of things, and they just mention that you guys could just backport the fix to 1.20.1.