Splitting this out from #5694 see #10545

Gutenberg uses a convention for keyboard shortcuts where the access combination translates, on macOS, to Control Option. Currently, there are a few shortcuts that use this modifier, including the new Blocks navigation menu implemented in #10545.

Unfortunately, VoiceOver on macOS uses Control Option as its own default modifier so all the Gutenberg shortcuts that use Control Option either trigger a specific VoiceOver feature or don't work at all.

So far, I've found the following shortcuts using Control Option:

Display this help. ^ ⌥ H
Open the block navigation menu. ^ ⌥ O
Remove the selected block(s). ^ ⌥ Z
Remove a link. ^ ⌥ S
Add a strikethrough to the selected text. ^ ⌥ D
Display the selected text in a monospaced font. ^ ⌥ X
Add link ^ ⌥ a (undocumented in the Help Modal, alternative shortcut available)

Basically, all the shortcuts implemented with rawShortcut.access() or <Shortcut type="access" .... All of these need to be changed to use a different modifier.

Aside: still thinking the best path forward is a mechanism to allow users to re-map and customize shortcuts, as proposed in #3218.