We've kicked around in great detail how fouls that carry over to kickoffs will be enforced. But we haven't talked much about how the R will signal them. For the basic case, say a 5-yard face mask by the defense during a score, it's easy. I would announce and signal the TD, announce and signal the foul, and then point at the 40. After the try, the HL will put the ball down on the 40, signal the foul again, and then pick up the ball and step off the yardage.
But what about the case where we have a personal foul by the defense on a successful try? Obviously the offense will want that foul on the kickoff instead of the 5-yarder. How do we signal this? I have two thoughts.
One is that the R will signal the foul on the try just like always, and that before the kickoff, the HL will then signal the original face mask, give the "declined" signal, signal the PF, and step off the yardage.
The other is to have the R do most of the work. (It's only fair.

) I see a sequence along these lines:
"The kick is good." (raise arms)
"During the try, personal foul... " (signal the PF)
"... against the defense." (point at the defense)
"The 15-yard penalty will be enforced on the kickoff." (point at the 40)
- (no changes so far, but then...)
"The previous 5-yard face mask penalty..." (signal the FM)
"... is now declined by rule." (signal declined)
What do others think?