KeePass 1.x (.kdb) databases can be imported into a.

Database files in version 2 can be opened, but will be upgraded to a newer format. But there needs to be enough to enable someone to get things working without danger of getting themselves in a lockout situation. KeePassXC currently uses the KeePass 2.x (.kdbx) password database format as its native file format in versions 3.1 and 4. I recognise that clear instructions for KeepassXC are not the responsibility of moz://a. If that is so it is far from clear how to make it work and therefore by fumbling around there seems to be the very real risk of getting in the situation where one has enabled 2FA but is unable to use it. You seem to be suggesting that the KeepassXC TOTP feature is what needs to be used for Firefox 2FA. Such things might be obvious to those that know, but for someone just trying to make sense in unfamiliar territory, the information and instructions there are seem far to terse and cryptic to be of help. It seemed to be talking about storing TOPT which sounded like a contradiction since I though the point was they are generated on the fly. I saw the reference to supporting TOTP (which acroynm is new to me so it didn't strike me as relevant to 2FA) but no indication of how that feature is supposed to be used and therefore how it might fit in the Firefox QR code challenge response scenario. Since there is no section on '2FA' in the docs I searched for '2FA' and also scanned every FAQ answer.

Keepassxc opera