The thing is that RM/AM is useful for already openEHR-savvy people creating openEHR tools and CDRs. Those that do that likely already have some kind of solution (e.g. hand coded), thus no rush and less activity seen. What is missing is modern version of the TDO/TDS/TDD approach as discussed in the thread Separating Models from Implementation - #75 by erik.sundvall.
(Of course some of the generated general RM class descriptions are usable also as e.g. data type descriptions to be included in the template specific “streamlined/flattened” approach)