No focusable inserter in zoom out

[jeryj]

Description

In zoom out, an inserter appear on the selected block at the end of the block boundary. It only gets rendered if this block boundary is visible within the viewport. When using a keyboard, this means there is no focusable inserter if the block boundary is not within the viewport, which is fairly common in zoom out mode.

Step-by-step reproduction instructions

• Insert a tall pattern that takes up all of the viewport in zoom out
• Enter zoom out
• Select the block
• Make sure the bottom of the block boundary is not in the viewport
• Press Tab
• Focus is not moved to the inserter

Screenshots, screen recording, code snippet

No response

Environment info

No response

Please confirm that you have searched existing issues in the repo.

• [x] Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

• [x] Yes

Please confirm which theme type you used for testing.

• [x] Block
• [ ] Classic
• [ ] Hybrid (e.g. classic with theme.json)
• [ ] Not sure

[jeryj]

A way to mitigate but not fix the core issue would be to add an inserter back to the top of the block boundary as well. This makes it more likely that there will be an inserter, but doesn't fix the core issue. The inserter should be able to be rendered without being in the viewport.