I can appreciate the challenges the OP faces having to reboot the system frequently. It's reassuring to know, though, that there are configurations where Roon works well.
I was also one of those with an early lifetime membership. Computers are a hobby of mine, and I enjoy administering all kinds of systems in my home IT closet. Roon core runs happily on my 14-year-old Linux server. I stream it to various locations with Intel NUC's running Rock, but mostly to my main 2-channel system with a PS Audio Airlens as the streaming endpoint. It's all controlled from either a Mac laptop or iPad.
My setup works great, but of course it requires a lot of computer experience. I think for a much simpler system, someone could use either a Mac Mini or a small inexpensive computer running Windows as their Roon core. I can definitely recommend the Airlens as a good endpoint; I stream DSD256 and 24/352 data with no issues.
Roon isn't perfect. I wish the search mechanism were a little more consistent in its results, for instance. But it does some things brilliantly, and is available in so many different platforms.
I'm not familiar with the Roon nucleus, so I really can't speak to that. There are ways, though, of making it work with basic computer hardware, and you can choose a platform that you're most comfortable with. It might be worth investing a little time to explore this option.
Michael

