I would like Firefox to save my usernames for sites, but not the passwords. However, Firefox insists that I supply a password before it will save the account details, and if I supply a dummy password, then it will not let me later edit the account and delete the password. I like to remember my own passwords rather than store them anywhere.

I have tried password managers and they are overbearingly controlling, particularly given that they don't store my passwords let alone my 2FA details, so I'd rather just use Firefox's less onerous, built-in system, if only it would allow me to save an account without a password. Surely saving a username without a password is a safe option, so why block it?