Thanks to KM8's new Prompt With List action, this whole macro has essentially been made obsolete in the best way possible. I've been able to pare it down from this:
to a single action:
There is a downside in that this version doesn’t support searching with regular expressions, but it more than makes up for that by being able to see and filter results instantly, and by being able to copy them to the clipboard with a single press of the Enter key (not to mention drastically simplifying the process of putting together a macro like this in the first place, making it easy to replicate the functionality for other files or lists). If anyone reading this is using the earlier version of this macro, or a similar macro, I highly encourage you to try a Prompt With List version instead.