Redox also takes some inspiration from Plan9 and https://doc.redox-os.org/book/ch05-00-schemes-resources.html is interesting. Also reading https://drewdevault.com/2022/11/12/In-praise-of-Plan-9.html made me a bit more interested in things trying to be more Plan9-like than Unix-like.
As long as it’s installed on a device you control it’s pretty easy to sniff TLS traffic from an Android application, even if they’re pinning certs. I do this all the time for work. Frida makes it extremely easy, even giving you the ability to edit boringssl if something important is happening in native code. I’ve had to do this a couple times.
If you don’t have root you’ll have to recompile the application though which could matter if you need the signature to not change, but that isn’t a common requirement.
It’d be nice to have a better way to test though; I’ve wanted to check out Waydroid. Some coworkers just use an emulator which works great if it doesn’t need specific hardware.