I dislike the need for these things, but for $35 and given the frequent length and unpleasantness of the T1 TSA experience it's not a bad deal. If you're worried about your connection and don't want to deal with rebooking if things go wrong, I would take it. Heh, I might even try this next time originating in JFK.

IME people frequently cut the TSA line (supported by airline staff) when they are at risk of missing their flight. One time I picked a slow line and there was so much cutting into it, I would've become at risk of missing my own flight were it not delayed.

If you try it do report back.