The standard Command-A keyboard shortcut in a UITextView is broken in Mac Catalyst 16/ Ventura with either TextKit 2 or TextKit 1 for long texts. In iOS 16 the selection is instant but on MacOS with Catalyst a beachball is displayed for more than 50 seconds and the app consumes gigabytes of memory.
Earlier versions of Mac Catalyst work fine.
To duplicate this just create a small storyBoard app with an editable UITextView and paste a long document around 1Mb then use the standard Select All Command either from the keyboard or the app menu. l I use Tale of Two Cities which is about 800k to test in my app.
Is there any workaround for this?