Difference between PRO VPI and PRO EN adapter (RoCE V2) (Hyperconverged Network, SwitchX connected to internet?)

What exactly is the difference between the PRO VPI and PRO EN adapter? Can the PRO EN adapter do RoCE V2? Are there any adapters other than the VPI PRO that can do RoCE V2?

Btw, My network is small (max 30 nodes), what benefits would RoCE V2 have over RoCE v1 for me? Is the routing only handy when working in large environments?

Are there any users that use their mellanox switchx as the all-in-one switch/router? Can you connect the WAN directly to the switch, and use it with the same functionality as a normal router?

Would 2 SX1036 switches be all the switching hardware required for small (sub 30 nodes) hyper-converged clusters? What other things would you advice on getting?

Thanks