Flew VCE-LHR-IAD on the 13th and used VeriFLY. Completed trip to UK and trip to US. Check in agent said he didn't care about the UK part (which I don't think is true, but whatever) though asked if we had completed contact tracing on MMB for the US (which I hadn't since we were returning home and didn't have a hotel to stay at which is what asked on MMB). Anyway, had to provide him our home address and phone numbers again to allow check in, though he didn't ask for any other docs (vax card or test).
Just a datapoint that I guess there is more needed for US flights that VeriFLY doesn't ask for.