Another option is to add a new admin user using xo-cli. Then login to XO as the new user and clear the OTP for the existing user.

Reping @nraynaud

But what about merging delta backup? This require write access.

Except if we completely "move" the merge logic in the storage itself (which will be possible in few months)

It's because it's a fake, edited to show how we would like to have it 🙂

If you need that, please open an issue in XO bugtracker, only after checking there isn't an existing same request 🙂