First post ever! Hope I do this right...
I had no problem clearing security at T4 to access Wingtips. I'm flying AA Economy JFK-MAD and used my passport + mobile boarding pass w/ TSA Precheck. No questions asked, no issues. The TSA agent did ask me my name and I simply answered "Sarah" and she was satisfied with that.
Spent 3+ hours in the lounge as I had a crazy long layover (came here via LGA). It does get busy after 5pm per the potential restrictions noted for Priority Pass but I entered around 2pm so no problem there.
Heading back on the Airtrain next to clear security at T8 and board my flight!