Look at a Small Language Models or Gemma4:e2b for generating comments on the server without paying an API for tokens. I explored running these locally for making a very unsophisticated chat bot and it was just slightly too slow for what I wanted, but you don't need instantaneous responses for generating comments on posts.
It's awesome! And it's always cool to me when I get a chance to look at a largerish CL codebase! Congratulations on all the hard work now mostly complete!