(this is not a bug)
I'm not sure how to report success, but I just had a few MisteryShield 20k M0S new version boards without the breakout board printed and built by JLCPCB and they work perfectly. I tested them with the Nanomig and the Misterynano core without issues. I know that no issues were expected but since you asked to report if they work, this is what I did.
This issue can be closed.
Thanks again!