It has been a couple of years since I have found any concrete statements regarding 802.11r and using it with WPA3. It also has been a few years since the release of the 802.11-2020 standard which contained H2E (hash-to-element) being put in effect. I assume it's still not a good idea to use both 802.11r and WPA3 together. But, is WPA3 now fully capable of applying Fast Transition itself and better client compatibility? Or is 802.11r and WPA2 still a better roaming scheme in a diverse clientele environment?
The IEEE 802.11 standards, yes.
The actual zoo of proprietary clients, not so much.
With WPA3, it is better to leave 802.11r disabled.