Hi!
Unfortunately, there is nothing information to help you.
I think that Microsoft focus SMB Direct only, because since introduction of Hyper-V shared nothing migration then Microsoft show a some product support. ie. MSSQL support SMB Shared folder, etc.
I have experience about Live Migration via SMB Direct but Hyper-V vSwitch was just a fast above 10Gb Network.
Maybe wait for Microsoft (also VMware,too) will be ready to support RDMA on their hypervisor...:)