Welcome, UmpnRef, to our forum. May you find it both informative and enjoyable.
The rationale behind this rule is if the foul occurred after the ball became dead, the action did not effect the result of the play. Same holds true on a USC foul with the childhood saying: "Sticks and stones may break my bones, but names can never hurt me

". The tricky one that I've seen us fumble on .....
(1) A team in a hurry-op offense gains a first down;
(2) team rushes up to LOS and snaps ball BEFORE RFP;
(3)

for DOG;
(4) Stakes would be reset to 1/10 after enforcement, NOT 1/15 as foul occurred BEFORE RFP.