Thanks for the update, did a few quick tests with PM 27.6.0. Permissions restore seems to work fine. I had problems with extensions restore.
1. Tried to restore 20-30 extensions at once: some kept endlessly opening tabs. They were extensions that did not require a restart and automatically open a new tab to alert the user to configure options etc. In this case, the same tabs kept opening continuously and I had to quit the browser.
2. Tried to restore only two extensions. See attached below.

3. Tried again to restore multiple extensions and got a similar result to FEBE 10.0 (nothing happens, restoring is stuck).