To be clear though, the OTG and external USB keyboard won't be needed if the user has the Hi13 rotary pogo keyboard, right? You focussed on the situation when the user doesn't have it, and that's good. I'm only trying to make the tutorial slightly more clear what it means.
Edit: also please make clear if both MicroUSB OTG and TypeC OTG works. So even a MicroUSB OTG connected to Hi13 TypeC with a MicroUSB to TypeC adapter should work as far as I can tell. Can you confirm? It shouldn't be necessary if connecting MicroUSB OTG directly to Hi13 MicroUSB would work also for updating the BIOS. Hackerjac confirms MicroUSB on Hi13 can be used for booting USB memory./Edit.
For those wondering what else the Hi13 keyboard is good for, see Laplets vs Tabtops (forum search).