Hello Chris !
Thanks for your mail.
1. hope an update for the multiple crashing problems comes soon.
2. Everything is saved locally on the local HD.
3. Affinity photo 1.7.2 responds quicker than Apple Photo 4.0. But editing in Affinity Photo on a normal harddisc @ 7200 RPM and with 'normal' Ram 8 Gb is slow and buggy; comparing with GIMP 2.10 and Pixelmator Pro 1.4.2.
We did some additional testing here. This time with the same iMac and OS spec's, but now with a high speed internal SSD and 24 Gb Ram. Responding of AP is much quicker.
From this point, I would advise to change minimal system requirements into 16 Gb + an advise of AP that AP will work better with SSD or Fusion Drive when using larger files of +100MB.
Also with the SSD and 24 Gb of RAM, AP still sometimes crashes (randomly) while editing/ tuning a layer. Also: layers are (randomly) sometimes not responding and need to be deleted and added again.
4. Already several people have send files and crash reports to AP. I am sure that the AP engineers have been able to simulate the crashes in their R&D lab themselves. Let's see what is cooking in the lab's.
5. :-)
Thanks and greetings from your neighbours in The Netherlands.