I am sorry I did not fully follow the discussions earlier.
I only recall it was supposed to exist some compatibility
layer at some point.
But I keep all the time needing to
$ sudo rm -f /var/lib/rpm/__db*
because I forget and use yum instead of dnf in rawhide.
I am not really needing anything special, just install
a package, or run "dnf update" to update rawhide.
Thanks,
Paulo