Syncing all about:config values wouldn’t work, since it contains lots of variables which are OS-specific or contain temporary values, like timestamps.
If you want to synchronize specific values, you can create a user.js file in your Firefox profile folder and synchronize that via file sync or Git or similar.
Yes, but it doesn’t synchronize all like the values in the about:config.
Syncing all about:config values wouldn’t work, since it contains lots of variables which are OS-specific or contain temporary values, like timestamps.
If you want to synchronize specific values, you can create a user.js file in your Firefox profile folder and synchronize that via file sync or Git or similar.