It’s stuff like “we enforce a naming convention for all bones”, or “we do a coordinate flip” or “limit number of material references”. It’s all bespoke custom stuff that exists in every studio but is slightly different, and project specific.

I’m not an animator but I do know that mayas rigging support is second to none; we’re often working on characters with 100+ bones and 200k triangles being driven by said bones. The standards stay standard for a reason when working at that complexity.