1) Are the BIOS proprietary? Same as Librem..
2) Has the manufacturer said it is compatible with Qubes? Seems they would want to test this themselves.
Have you reached out to them? Was tempted to do it myself...
I tried sending a note to Majora, they have a Forum and a Feedback link. I sent them a note on the feedback link but it just clocks...I didn't want to sign up for the forum so didn't ask there.
Maybe they will respond here?