I mean that an !$OMP DO directive can be set upfront a do concurrent construct. You say that it’s not possible even in OpenMP 5.2, but I’m not sure I agree. While the OpenMP specification was clearly stating the “[the use to DO CONCURRENT] may result in unspecified behavior” until the 5.0 version, this warning has completely disappeared in the 5.2 version.
However, assuming it’s possible, it’s really not clear how they interact.
Anyway, I tend to not use do concurrent at all, as I find OpenMP extremely simple, with generally efficient implementations, and much more control on the locality of variables, on the scheduling, etc…