I also use an miniPC (mine's AMD not Intel) for my home imaging setup. I find KStars/Ekos to be perfectly comfortable on the Pi4, but occasionally I do lunar and planetary and for high-frame rate video capture the Pi just can't come close. I can get anywhere from 3x to 5x or more frames per second on the miniPC. Once it's out there under the scope there's no point swapping it back out for the Pi.
On the other hand, I use a Pi all the time up at my cabin or on the road because it's so much power efficient. I have no line power at all at the cabin, so everything has to be charged off solar, and I just can't see wasting watts on a miniPC.
I rarely compile anything on the Pi, and just work with the ubuntu repositories. Running KStars is just no trouble at all on the Pi, especially when I'm asleep! The interface is just a little bit laggy compared to the mini, but not so much that it bothers me.