I went back to ArrowOs v10 for two reasons.
The main one is that the bank app does not install because it says root permissions are enabled and therefore security is compromised.
The second is that the navigator I use from Oreo with android R does not work but this would not have been a big problem, I would have updated it.
Overall the experience I would say is positive, when ArrowOs will not be updated it is definitely a good solution to keep our devices updated, I will have to find a recovery compatible with Project Treble that does not enable root permissions or at least that does so only if requested (I tried the unroot function from recovery but it didn't work).