I did do a search, but purposely wanted to bump a new thread in hopes it would gain attention again. I wasn't aware though that the cause had been identified. It would be fixed by moving the verification process after the initial UI loads however, though I'm not sure if that's possible with App Store submitted MacOS apps. Could be right in that case, it's an Apple thing - though these Affinity apps are the only ones purchased from the App Store that have this poor loading speed on initial load.
To me, it's annoying enough to warrant moving to something else as it's been a lingering issue and speaks to some degree to the quality of the software and/or update cycle in general. However, since the software is on sale I've now purchased a copy of both Photo and Designer directly vs the App Store. Solved the issue now, loads instantly.
Re: the system specs ... I'm running dual XDR displays with the system as well, definitely a beast. Beautifully designed system. I'm a hardware and software engineer / developer; developed software that interconnects with custom developed hardware for NHL training centers etc. as well as many other integrated systems like shipping & tracking etc. I don't often max out the system at all, but it's there should I need it and it runs dead silent, and pushes these two 6K Apple XDR displays plus all of my attached external storage and other hardware I develop for / with, with ease