Conserver la synchronisation Firefox sauf pour une extension
https://www.reddit.com/r/firefox/comments/1065lph/firefox_sync_but_choose_what_extensions_are_on/
“If you want add-ons to download across devices but only want to activate a specific one on a single machine:
1. Open a new tab and type about:config in the address bar.
2. Accept the warning.
3. Search for services.sync.addons.ignoreUserEnabledChanges.
4. Double-click it to toggle its value from false to true.
This prevents your activated/deactivated extension choices from syncing with your Mozilla Account.”
1. Open a new tab and type about:config in the address bar.
2. Accept the warning.
3. Search for services.sync.addons.ignoreUserEnabledChanges.
4. Double-click it to toggle its value from false to true.
This prevents your activated/deactivated extension choices from syncing with your Mozilla Account.”