Regrettably I got locked out of my Sync account due to losing my 2FA and recovery. Giving that to err is human and data losses happen, I had hoped that there would be an alternate method of resolution, even if it means that the account is deleted so that the end user can use their primary e-mail account. Given that my account login is my e-mail address and my e-mail address is the equivalent of a company holding my name and address I assumed it would be possible to use an official request for data removal. Unfortunately Mozilla will only remove your e-mail address from mailing lists and not from sync account servers. So, it would appear that once you lose your 2FA, Mozilla can retain your personal details forever, and there's nothing you can do about it. Essentially what I got back after waiting for a month was being removed from any e-mail subscriptions and a 'get stuffed we can't help you, here's a link that we know can't help you'. Pretty bad after waiting a month. It certainly makes it very secure, I'll say that, but also very weird to have an e-mail address that is unusable for the next few thousand years. Essentially on a blacklist. Having moved to Firefox after Netscape Navigator it's a shame to be locked out or to even be able to delete the account so I can start again. Anyway, my account sync with Edge and Chrome on both my Kubuntu and Windows install work fine so it's not like I don't have a browser that won't sync. If anyone does have a solution, I'll take it, but after a month of trying various methods I think my e-mail address is now useless for Firefox Sync, and thus Firefox is now useless to me and I'll have to use Edge and Chrome instead.