I 100% agree with the idea of translating lingustically "mismatched" posts after they have been made. This allows ideas to flow as quickly and freely as possible, and clarification for people who speak other languages to (hopefully) promptly follow. I'm going to respost a comment that I made to someone in this thread: Language of esperanto.stackexchange.com
It's just an idea, not exactly a proposal since I haven't spent much time thinking about it in-depth and I don't have previous experience with StackExchange, but I'm curious for some input on it, to see whether it is worth improving or if it's just more effort than anyone here is interested in:
I think it could be useful to have in place a system where, if someone does come along who doesn't know English or Esperanto well, they can still attempt to submit a question and with our pooled resources here we can help convert their question to English or Esperanto. That leaves them with the problem of receiving answers only in English or Esperanto, but perhaps someone who knows their language can assist by voluntarily translating certain answers by request. It's not perfectly fair, but it at least provides some method for non-EN, non-EO speaking users to participate.
In addition, I think it would be a way to involve the vast part of the Internet that isn't English or Esperanto speaking into this Esperanto Language StackExchange resource, without it becoming incredibly chaotic. It would be more of a volunteer type service by our polyglot/bilingual users, not an obligation, and not a linguistic free for all, either.
Whether or not this concept is applied to all languages, I think it would work decently between at least Esperanto and English. If someone requests a post be translated either into Esperanto or to English, it's clear that there is someone here with the cability to do that, and because this site is all about exchanging information, it seems likely that if a request for translation is made, someone will voluntarily provide one eventually--especially if such a practice becomes encouraged and systemized in a way that it wouldn't make threads look cluttered and disorganzed.