Activator performance improvement

Shouldn't close the previous PR early. Turns out I did not have to change much of my design.

Pinging previous trackers
@pranavkm
@halter73 
@rynowak
@ipjohnson
@yishaigalatzer 
Yeah let's figure this out. I think we've already seen cases where the current behavior is a bit confusing, and just saying "best match" is indeed quite vague, especially if there are two "longest" matches.