This is over four years old, but I think it’s still relevant. Apparently, the defense can’t get a 12 men penalty in that situation:
“If a play takes place and a defensive foul for too many players on the field results, no penalties will be enforced, except for personal fouls and unsportsmanlike conduct, and the down will be replayed. At this time, the Referee will notify the head coach that any further use of this tactic will result in a penalty for unsportsmanlike conduct.”
Offense not allowed to quick-sub and quick-snap