This REALLY should not be the case at all.Be careful, after updating PART2 , I no longer have access to my chips anymore..even if I follow the right instruction by double clic reset button in payload update
The chip still work like a charm, but no longer accessible
The UF2 bootloader is standard, with a couple of memory option added, to choose which straps to drop.
There is no possible way you can be truely locked out.
You can:
Long-press VOL+ for around 30 seconds, wait for white flash, power off console, power on, reconnect.
Double-press RESET as usual
Even if the chip is BRICKED SOLID, eg you have erased 0x00000000 to 0xFFFFFFFF you can always bring it back with openocd / SWDIO.
Something HAS to be slightly amiss your end. I`ve tested on Windows, Unix, that Mickey Mouse OSX, even tested mass-storage drive on AmigaOS with varying degrees of success(don`t ask. Drunk and bored.)