We are currently finalizing the 64-bit version of PT4 and I expect it to be publically available before the final release of Catalina, but if you open a Support Ticket we can send you an alpha version which supports Catalina now (but isn't fully ready for public release).
So I understand that they do not have the final version yet. But is it normal that the HUD is not really working right now? Because for me it shows the HUD for 1 or 2 hands and then it disappears.