How did you implement /q? I'm working on it and I've thought of two ways:
* on every /q request, rescan the entire thread for anchors that would load the q parameter; this is slow even when it isn't being done in PHP.
* keep around a cache of what anchors every post requests; this isn't slow, but adds more data files which might annoy someone, and makes me wish for an actual database. Also, it can get corrupted and has to be updated every time someone posts and such.
Well, as an experiment, I've implemented both the q syntax, and http://wakaba.c3.cx/sup/kareha.pl/1102984488/1 on these two boards. Try it out, and give suggestions for improvement or changes.