It seems that iOS/iPad WebKit has issues with USB based microphones. At least this is the answer I got from Rode and was able to validate myself with some simple checks.

If not a full blow iPadOS app as wished in the https://feedback.descript.com/feature-requests/p/ipados-app - may be you could at least create a simple recording app based on your skills from Squadcast?

The problem is really the WebKit interface, so the app must be kind of native for the recording and the connection to the USB-C based microphone.

Thx for considering