Good catch. So they must set or shift into a scrimmage kick formation and a scrimmage kick formation is defined by snapping the ball with the holder/kicker or punter at proper distance behind line.
With that in mind, if any 50-79's are replaced during a try, can K run a play from a swinging gate or any formation other than a scrimmage kick formation?
If K snaps the ball from scrimmage kick formation with 50-79's replaced, can they fake the kick with a run/pass play?
First, the only thing that's required for a scrimmage kick formation is the location of the potential kicker (and holder for a field goal). The rest of the line can be wherever on the field. The "swinging gate" play will often have the snapper, holder and kicker in "scrimmage kick" locations and the rest of the line is way off to the side. This is still a scrimmage kick formation as long as the kicker/holder are located correctly.
The snap at this point does not have to go to the holder, it can go to the side (as long as it's done legally). Also, if the holder does get the ball there is no requirement that a team kick from a scrimmage kick formation. They can absolutely fake the kick and run or pass the ball.
What they cannot do, as far as the numbering exception goes, is shift into a scrimmage kick formation - establish non-50-79 players as linemen, then shift OUT of the scrimmage kick formation and retain the numbering exception. If they snap the ball while NOT in a scrimmage kick formation, they need 5 players numbered 50-79 on the line to be a legal formation, regardless of down.
