I actually noticed the same. Having it work on Mithril.js instead of React seems (I know it's all just kind of hearsay) to generate a lot cleaner code. Maybe it's just because I know and like Mithril better, but also is likely because of the project ethos and it's being used by people who really want to use Mithril in the wild. I've seen the same for other slightly more exotic stacks like bottle vs flask, and telling it to generate Scala or Erlang.

That makes sense. There's less training data but it is better training data. LLMs were trained on really bad pandas code, so they're really really good at generating bad pandas. Elixer, there's less of it, but what there is, is higher quality, so then what it outputs is off higher quality too.

That's been my experience as well. Claude code does better with Elixir (plus I enjoy working on the code better after :) )