In NCAA you'll see the officials who have the spot raise one hand. This is the signal to start the 40 second clock, although it sometimes takes a couple of seconds. The R does not need to blow an RFP signal except in cases where the clock stops and is restarted. Then there are 25 seconds, if I have that right. I'm not totally versed on NCAA rules.
HR6, I agree with you but there's nothing in the rule book about it. If they have 25 seconds to snap it and NCAA has 40, that means, at most, they should get 15 seconds between the time the ball is ruled down and the RFP. To me, even that seems a tad long. I try to be consistently 11-13 seconds. No way am I waiting on a QB to go for a sideline chat before my signal, but for some reason some referees might.
Like I said, there are lots of discussions online with referees on this topic and the vast majority, if not unanimous majority, do not wait around like that. Of course, we are the referees who care enough about it to take the time to participate in such discussions.