There’s also the deep computing mainboard from framework. Also that p550 uses a new CPU while the mainboard uses a jh710.

The p550 is less rpi and more like those rockchip powered boards from radxa. (ignoring core count).

Yes, but it doesn’t have arm levels of growing pains.

Current risc v SBCs are about 10 years behind performance wise, which isn’t as much of a problem. Core count is there, just not single core performance.