I built all my apps this way and faced the same problem as OP - so had to buy a Mac mini. It was the cheapest option ~8 years ago and I still use it today for the same purpose - just for compiling. I assume there are probably more of us.
About 50% of my MacOS usage is replicating bug reports from users. I don't know how I would do that without having one on my desk.
Maybe more iOS specific bugs are introduced when doing iOS specific development (like using iOS tooling and techniques).
My only need for a Mac with expo is for the upload. The apk file is taken care of with the command above.
I have an iPhone I use for development and testing. Bonus points is that expo is cross platform, so I can publish to google play with the same single code base too.
I'm glad it's working for you, so far, but try to do anything slightly interesting and you'll have problems.