2 comments
I'm sure it's not what you are looking for, but GT New Horizons is a 1.7.10 pack actively being updated :) (version 2.3.4 was 11-Jun-2023)
I can't think of any others off the top of my head.
Reika's mod pack maybe? I think at this point that doesn't really extend beyond updating Reika's mods to their new versions when one gets released (so twice a year or so), but that's still more activity than basically any non-GT 1.7.10 pack.