Excluding Nyaa or private trackers, as many ongoing and more obscure titles aren’t available to torrent. I’ve been using Comick and Weeb Central, but I don’t really know how up to date they are on new scanlations as I think they’re mostly aggregating from other sources?
TachiJ2K is the fork that debut bulk migration, and, while relatively inactive, it’s technically still maintained. It’s very much feature complete though, so I wouldn’t much about it not being super maintained.
Personally, I’ve been using Yokai, it’s basically J2K, but actively maintained and getting feature updates.