As part of the fb40m restart procedure (Sanjit and I were restarting it to add some new channels so they can be read by the OAF model), I checked up on how the backup has been going. Unfortunately the answer is: not well.
I'll check in with the frame builder again tomorrow, to make sure that it's all good.
All is well again in the world of backups. We are now up to date as of ~midnight last night.