No way to combine "regex" with "input"

[mcclure]

So, I have a goal: I want to make a feed consisting of every post I've ever made with a particular string, plus some other posts I add to the feed manually.

I add a "regex" block with the phrase "listening to"; I add a "Single User" block with my user id; I add some "Single Post" inputs. Except, wait, oops! These are ADDITIVE. So this is adding all posts with "listening to", by anyone; all posts by me; and all posts with single-post blocks. If I remove the "single user" block that won't help really, because that will add all posts with "listening to" by ANYONE and I only want posts by me.

I don't think the thing I want (a regex search limited to a single user, single list, or single feed) is currently possible. This would be a useful feature.