Is it just as easy to make an extension that runs a local AI translation model? Translation would benefit from having a community continuously updating and tuning local models for languages.

If it was an extension it would be nice if people could fork it with other models. Just like their AI Tab Grouping feature would be much better forked with a deterministic non-AI grouping system.

I had a translation extension for a good 2 years before it was built into FF

Sounds like a great plugin.