I’d retry in v4.2, there’s been an microg overlay fix that should provide basic integrity again for a linked Google account. That could be enough for some of them to send the sms.
Q1: Relocking is nice, but for the “basic integrity” verdict it needs (afaik) the tethered Google Account too. You can try in v4.2 without
Q2: Relocking resets your userdata on the phone - yes, disruptive
(ultimately, it’s cat-and-mouse though. “basic integrity” is proprietary, not a neutral term - and constitutes market manipulation in favor of Googles rom signing keys)