Much of any V2 vs V3 changes wrt gateways is around the look and configuration of the console, so basic principles still apply, the big change being the target LNS address. If using a standard (UDP) packet forwarder vs something more secure/recent such as BasicStation. In former case you usually need to just log into the GW and retarget to (e.g.) “eu1.cloud…”. retaining Port 1700 rather than the original V2 server. If using BasicStation it involves enabling the associated security keys, port settings etc per documentation. Others with specific knowledge of the iFemto-Cell will no doubt step in to assist with the details if needed.