I tried to offer a gentler backgrounder on this HCI business: lemmy.ml/comment/17160273

The opcodes that actually jumped out at me more than the undocumented ones were the ones that erases the flash.

But the conclusion stands. None of this is a ‘backdoor’ unless you can secretly access it from the wireless side and nothing in the presentation points to that. If I had to guess, the opcodes are for QA and tuning on the manufacturing line.