Enhancement pack no longer functions as an add-on module, and are partition into two category i.e. interface-mod and familiar-mod. Download links are now available again.
familiar-mod will be renamed as art-&-model-upgrades. What's inside art-&-model-upgrades? -fixed a proto-issue on familiar-mod, causing it to crash to desktop. -otis have a new model, plus beard hair. -rannos davl have a new fat model. -glora gundigoot have a new model. -familiar art and model overhaul. -familiar black rat turns white.
I don't know about dev-level compatibility with 8.1.0, but I assume it isn't since it's never been declared so here. I can tell you there are no plans to include this work officially in the modpack though, so if you use it in your mod(s), you'll be taking them out of the future modular compatibility zone.