No more info beyond what I said in comment #28.
Running room correction on the WiiM home app generates a set of PEQ values for your device, but equally you could have obtained a set of PEQ values from any other app and simply populated the PEQ screen in the WiiM Home app - indeed, that’s what I did with HouseCurve before WiiM intoroduced RC on their iOS app. So, yes if you get REW to generate your PEQ settings, you can enter those into the WiiM app PEQ screen.
Edit: indeed if you borrow an iOS device and run RC on that for your WiiM, you can then see the results in your android app as the resulting peq values are stored on your WiiM device, not in the WiiM home app.