Thanks for the details about your network. That’s pretty locked down. Your studio network may not have DHCP, but that’s not tied in any way to having internet access. For example, I have a Ubiquiti network that allows each VLAN to have a separate DHCP range, and each VLAN can have different access via routing and firewall rules. It’s no problem to lock down internet access (or cross-VLAN traffic) into or out of VLANs without turning off DHCP, and each port on the switch can be locked to one (or more) VLANs.
I realize that your thread is really about asking Eventide whether your H9000R can be upgraded or traded for one with a front panel, so I’ll stop here. There is definitely a network solution to your problem however, and it might be cheaper than this route.