Hello @jacodebeer ,
There is not work-around since the minimum software can run the R350 is 200.10 and the R310 is a end of Life product which the maximum software it can go is 200.7.
There is a gap in software, features, compatibilities, so both can not coexist on the same network.
You can create a new VLAN/Subnetwork on the network to deploy the R350, but this will not not roam to the R310.
