I was seeing this long boot issue on a clean install of Monterey 12.3 with Affinity Photo 1.10.5. It did not matter if I opened the applications previously or not, the boot time was always extremely long. Duplicating the app to the desktop and then overwriting the original with the copy did indeed work. When I first opened the new copy, inside the Applications directory, the "Validating Affinity Photo..." dialog flashed. This makes me think it has something to do with certificates and apple security procedures. I'm certain that Serif can work around this issue but boy has there been some foot dragging...
