Option 1 should work for any image on the eMMC that’s not older then 2020 at this point…
I suspect my EMMC has an image older than that, it’s a Debian 9 system still with a 3.8.x kernel.
I think I can probably muddle through as I am, I am actually on the boat where the BBB is at the moment and I will be for a couple more days, so I can push the button when needed. Then, before I leave and only have remote access, I will copy the SD image across to the EMMC. I’ve already got the ssh tunnel access working on the Debian 11.7 image so I can access it remotely. It’s hardly a major disaster if it all goes pear shaped, I’ll be back again in a few weeks time.