I now have the final Elf meshes in engine, and can confirm that all the slime animations play perfectly on them. I'll be releasing a new version by Wednesday which will add Elf Female and Futa models, and all of the animations associated with slimes. Elf males are not yet complete, but will appear as futas. Since they weren't done in the original anyway I don't think that's a big compromise.
In this version Elf animations will work with all combinations of Player, Neko, Slime, and Harpy.