I realize that as per the ask/don't ask the answer is "no", but if I go to StackOverflow how many people are going to answer a question about Fish or CJam?
I feel like questions about golfy languages maybe should be on topic here.
I don't think they are on topic here, because where do you draw the line for what counts as an esoteric language? The fastest way to get help with these languages is probably in the PPCG main chat.
But I would actually suggest you do ask them on Stack Overflow (provided it would be a good question for SO if it was about a "normal" language), and then leave a link to the question in our chat. Seeing the Brainfuck and Befunge tags, there is definitely precedent for questions about esolangs on SO.
Note that "provided it would be a good question for SO if it was about a "normal" language" is really important here. SO does not like questions about golfing code, be it in an esoteric language or not. If you want to ask for advice in golfing something (in any language), this belongs here on PPCG with the tips tag.