I did the downgrade from 7.0.0. to 6.2.0. without factory reset and everything worked perfectly. Why is it strongly advised?
I still did not power off the switch since I downgraded and now I'm planning to create EmuNAND 6.2.0. and then restore my NAND backup from before the downgrade to avoid any more fuses getting burned.
when downgrading there are thing that can mess up if you don't. I've seen mixed cases with 7.0.x down to 6.2 of working and not working