iodéOS 2.10 → 2.19 update don't work

Hi Miria, I have never tried to flash a device, so I cannot comment on your efforts, but they look impressing (and complicated)! I just downloaded a new updater from github as beta-tester, since (again) updates didn’t work. But now the phone is stuck to the start screen with the “iodé”-lettering.
LVE tells (Mise à jour bloquée à 2.11 - #3 by LVE) there are more of us with the same problem, but apparently Antoine from iodé didn’t help either.
Any suggestions how to go to “factory-settings” with the startscreen stuck? It IS frustrating indeed!