After my first flight on Frontier, I needed a chiropractor (see Not Breaking News: Frontier Airlines Sucks). Fortunately, there was a Priority Pass in the terminal. Unfortunately, I could not enter it until three hours before my next flight on the Frontier hell bus. I was disappointed to see that the coffee machine was not working. I was relieved to see that the food was halfway decent. 
Seating
It makes sense why they restrict access to this lounge. It was packed when I arrived and packed when I left. 
Bar
I tried to preemptively numb myself before the next leg of my flight but could not muster the will to drink.
Overall
This was a pleasant interlude before my next miserable flight on Frontier.
I find the other “The Club at MCO” in terminal B to be a good bit larger, less crowded, and generally nicer overall than its counterpart in terminal A at MCO. On a long layover in terminal A, I’d say it’s worth it to head over to terminal B, even accounting for the fact that you have to go landside and redo TSA. MCO is a madhouse almost always, but they always have full-on precheck (not precheck lite) going and they move you through pretty fast. Even faster if you have CLEAR.
Thank you for the comment. I hope to never connect through Orlando again, especially on Frontier, but if I do, I’ll know where to go.