Originally Posted by mander
If you have to force deflection it's probably too tight. I like the slack in my chain to feel a touch floppy, not taut like a bowstring, so when you deflect it you are actually just lifting it up a bit, fighting gravity not chain tension. That way you're sure it's ok. There's really no safety related reason to have it as tight as possible without binding and it's too easy to get it too tight and mess up your bearings and drivetrain.
What kind of stretch should I anticipate? Should I leave it as is and wait to see what happens, or do I throw the half-link in there?
It's not binding in any way that I can see, then agian it hasn't been placed under any load so I'm not sure.