We have a lot of technical debt but then, well, maybe. However, most likely at that time it would be already Raspberry Pi 5 16GB Edition ;-)

I doubt they would ever catch up to the hardware requirements of a witness node.  They are getting close to Mira, but the CPU and Bus are so ridiculously slow it likely would never be able to keep up.  Not even sure if you can get hived to even compile.  That in itself would be a challenge if you want to see how far you can get.

With full Ubuntu support for the Raspberry Pi, it is more likely a reality than it was before, but who knows what utils are not supported on Pi yet.  I wouldn't hold my breath.