I'm running Android app of my bank on my Librem 5 via Anbox. It's rough, but it works for me - YMMV.
Edit: looks like you're already aware of that :)
You can set up Anbox on your PC and see how that works. It's the same thing on the phone.
But I don't know if a full emulator is a good idea on a smartphone.
There's also Waydroid, which works by implementing things like Wayland/PulseAudio clients directly inside Android compositor/sound system, but I haven't ran it on the Librem 5 yet (I know that some people are using it on the PinePhone).