Corrupted bootloader after iodéOS installation

Thank you very much!

Now I’m a bit shocked and I think I’ll keep stock FOM for a while. I’d just like to understand, at least conceptually, what’s so important about the ‘critical’ partition and why for some OSes like /e/OS it needs to be unlocked and why for others (like iodé) it doesn’t.

Basically: if I installed /e/ tomorrow and then wanted to switch to iodé, how would I do it? Would I risk a new phone brick?