I also wish there was a way to disable the “disable paste” feature.

Worst case, if there is bizarre breakage due to frameworks that reinvent text boxes, have a keyboard shortcut or menu item to type the clipboard contents at 300 characters per minute.

There are some extensions that can help with that:

https://addons.mozilla.org/en-US/firefox/search/?q=enable%20...

Specifically: Absolute Enable Right Click & Copy

I would prefer of course that the underlying issue get resolved, but in lieu this has been an excellent workaround for my needs.

Ctrl + right click may allow you to work around it.