Is there a way I can manually add a Mac app to an item's Linked Apps other than via Quick Access?

Jack_P_1P That works for me indeed. I have to mention that I'm already on the beta channel due to an earlier bugfix so that might help @misterbiscuit. And although this way of using the app works it requires a different action from the user (different key strokes to open the quick access, need to accept the quick acces item with Shift+Return otherwise it opens in the browser instead of the app) besides the usual ⌘+. And you first need to realise that 1Password filled in a different password for you which is difficult to tell when it is masked.
Not sure what a good solution would be though.