[anonfwd7]

Use a different Firefox profile for work/personal.

Sign-in to personal (while at work) to sync bookmarks if firewall allows. Depending on whether you trust your employer you could sync further personal settings.

Don't sign-in to work profile and no work bookmarks or settings/logins get shared.

Don't get me wrong: multi-account containers are a blessing for those rare days when you absolutely have to log-in to facebook.

[esnard]

What are the differences between a profile and an account?

[anonfwd7]

I suspect the mapping between accounts and profiles is 1:1, but you can have a different profile which is not associated with an account.