I wasn’t aware Arch had builds available for arm, I will certainly give it a look-see.
Unfortunately the Orangepi 5 is somewhat shitty to hop around with, many builds either don’t support the RK3588 at all, or certain things just don’t work at all on most (I’m looking at you GPU acceleration).
On top of this, the SPI flash can be quite a pain to work with, due to orangepi doing the bare minimum to ship the product, I would really love to see dual-boot in future for it, though my expectations have been seriously tempered when it comes to orangepi.
The result of this, is that any distro I installed to the SSD removed boot priority from the SD slot, ergo, without formatting/overwriting the SPI flash, it will refuse to boot from SD, even with no SSD present. Some builds boot fine from having been directly flashed to the SSD, so far Batocera, Ubuntu and the J-Reik Rockchip Ubuntu have all booted flawlessly when directly flashed to the SSD, no luck with most others though.
I must admit though, that RK3588 is blazingly fast for how little power it draws. The hardware is top notch, I just wish the software weren’t lagging so far behind. If I remember rightly the incoming kernel should resolve many of these issues, I believe it’s still running 5.10 currently.
Apologies for the rant, during my writing of this reply I came across a repo on GitHub that someone’s been building for the Orangepi, I’ll give it a shot and hope for the best I guess! Seems to have rkbootloader paired with it, which might help dodge the bullet that the SPI flash can feel like at times.