I've been thinking of more extensions to that. The only useful one that I can think of is 'qX', which would display every post with an anchor to X. That would be kind of slow, though.

Requesting implementation of Shiichan's comma syntax to refer to well-defined sets of certain posts.

Like this: http://www.world4ch.org/read.php/vip/1103880078/47,5,15-10,8-

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.