Are you going to be hosting things for public use? Does it feel like you’re trying to figure out how to emulate what a big company does when hosting services? If so, I’ve been struggling with the same thing. I was recently pointed at NIST 800-207 describing a Zero Trust Architecture. It’s around 50 pages and from August 2020.
Stuff like that, your security architecture, helps describe how you set everything up and what practices you make yourself follow.
I have an iPhone and a gl.inet gl-e750 portable cell router, and my SIM card stays in the router. I don’t actually restrict my phone the way you’re talking about, but this gives me vpn to my home network without needing the vpn running on each client device. And if I wanted to block connections to big tech company services, I could do that.