I’m sorry to have missed this — I’m very much interested in C++ binding and interoperability issues.  I know Jeff at least is involved in our weekly C++ heterogeneity phone meetings — we’re trying to move the Standard to support multiple memory spaces in a sane way, and I think it helps to have RDMA represented there as well.  We’ve also thought a bit about wrapping MPI RDMA in Kokkos, and about making the mdspan proposal flexible enough that we could perhaps support RDMA with it as  well. The most interesting bit might be actually introducing semantics for noncoherent shared memory into the Standard — I think we want to go there eventually but it is really hard, and I think y’all are well equipped to help.