If you can use Arch Linux ARM as the OS for the RPi device, you may want to use already available packages for such platform. See ongoing discussion here.
That's a great option. Also, the technical preview version (5.11) can be downloaded from new Raspbian Buster repository. My problem with these solutions is that I want to install PySide2 as a regular python package, so I can handle all dependencies of my application in the same way. That's the reason I'm using custom wheels. But, of course, Arch Linux ARM job looks amazing.