How does the OL know whether to run or pass block in this RPO scheme?

They run block every RPO. The challenge is to not go too up-field on their blocks so as to not get an illegal man downfield penalty called when we decide to pass.

They don’t.

If Burrow passes, he has to get it out quick to avoid the OL from getting too far downfield while run blocking.

I doubt that refs pay attention if the block begins within 1 yard of line of scrimmage and block is held while pushing defender beyond the 3 yard mark. If on a LB setting back and moving laterally big difference.

It used to be that a blocker if maintained their block could push downfield as far as they wanted. That is not the easiest thing to do for any blocker.

RPO the o line run blocks on every play. Have to avoid ineligible receiver down field. We have had a couple of those not called. No doubt they will call it in Tuscaloosa. Although they run RPO as well. Whatever.

On the TD pass to Chase against Florida, Lewis was close to the distance down field that could draw a flag.