Checks completing flicker when they are really fast

[technicalpickles]

Currently, scope run shows a tree of all the checks as they run, but then hides them when complete. I think for an end-user, it can be a little disorienting to see them pop up quickly, and then go away.

I'm wondering if we could do one of:

1. keep the check there, with info about it finishing successfully, how long it took, etc
2. keep the check there for at least a few seconds so it's not like an immediately flash