You have to install all necessary packages but it will work with (IPOIB).
The IPOIB stack is the Vendor/Debian part and not included in Proxmox VE.
So the enterprise support does not cover this stack.
I'm not deep enough in the ceph code to answer this question 100%.
But we have an RDMA patch what fix the "msg-async-rdma-uninitialized-variable-fix"
I guess this is what you are talking about.