When switching from 1.2.2 to 1.3.0 during a modpack update, variants from other mods other than minecraft and moremobvariants (like copycats:copy_cat) are no longer in the variants table. Attempting to manually set a cat to have this VariantID fails and reverts to the default texture.

I'm presuming it is related to the new calling of clearAllVariants() and the logic therein within the Variants class that started with this commit:
0afa299

Desired behaviour would be that this mod does not wipe out other mods variants, but instead uses them as part of its pool