Ooh, this is something I have contemplated making for a while. I think a really good way to get sophisticated filtering is to allow filters to be specified in

Ooh, this is something I have contemplated making for a while. I think a really good way to get sophisticated filtering is to allow filters to be specified in snippets of JS (or LUA) that are then executed by a sandboxed interpreter that presents the filter with a very restricted “DOM” representing the post+feed metadata. Include things like author and title and body and links, and let the user do whatever filtering logic they want. And if you really wanted to make it user friendly, instead of having them edit the code, give them a blockly UI for the filter editor. You have to limit the CPU time given to a filter to avoid runaways but that isn’t hard.