Exceptions are not part of data that is synced. All exceptions (logins are an exception) are stored permissions.sqlite in the Firefox profile folder.

• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data
• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

Nice. Would it be possible to add exceptions to the syncing list in the future?

Right now, no site permissions/exceptions are included in Sync, whether that is pop-up, camera, notification, or cookies, etc. Is it possible this might be added in the future? I really have no idea...

Mozilla has a product suggestion site at https://connect.mozilla.org/. I think if you have time, it would be a good idea to post this request there to get into the current feedback stream. Use the "Ideas" section of the site.

Alright.

Yeah I should do that. I've just noted that previous, similar posts to this one have requested functionalities that have been flagged as probably never being implemented.

Brave browser syncs exceptions, no reason why Firefox can't implement this. It is a massive usability improvement for people that are privacy centric and use multiple devices on a daily basis. Having to manually add an exception to every device I use Firefox on is a pain in the ass. Unless you are OK with users just getting fed up and going back to Brave, etc.