It sounds like that every country has a different distribution of used models. Backwards compatible consoles sound great, but I wouldn't risk destroying it just for this purpose. Maybe we can find someone who has a NAND flasher installed already, eventually.
I can't really provide much help regarding this. I only used E3 NOR flasher for my bricked Fat and I didn't have any luck with the clip, so I had to solder it directly. That unfortunately resulted in a torn off pad and I barely recovered the board (had to solder a wire between two points, it barely hangs on there). Slim models looked much easier in old videos, mostly because you can run it outside the case with a
clamp like in this video by NSC. I'm also going to try that when I get some time and that awful security torx T8 bit.
Be aware that most of the ones from China and such are clones, so it might be better to find a used one somewhere near you.
Fellow network device modder here, that is so cool. I have destroyed so many second hand low cost TPLinks and ancient Routerboards before doing the first successful SPI flash and RAM chip swaps. The only way to fail that is to give up trying.
As for the Syscon UART test points, I think you can destroy the pads without breaking the board (at least on Fat models). It should be connected the same way as the ones in routers, as opposed to NOR flash test points that are a part of the NOR chip to south bridge path. Maybe there are some other things to watch out for, though. We are lucky to have RIP-Felix and others who specialize in Syscon related stuff on this forum.
