As far as I realise PT4 starts to load the stats of ALL popups once you click on to show any of them. If you have several popups and your popups includes several complex custom stats then it takes a long time, sometimes even 20-30 seconds even running it on a good computer (i7 Processor, fast SSD, 8-16GB RAM.)
I suggest you to make PT4 to not start to load all the stats of all the popups but the only one which the player intended to see that time. I suppose it's not very difficult to do and it would increase user experience a lot.
(As an alternative solution you could make PT4 to cache custom stats, too, or start to load all the stats of the popups immediately once the regular HUD stats got loaded.)
