-Allow isolated networks to use same variable store and remain isolated. (using variable store faces)

Something exactly like this won't be implemented, but perhaps subnetworks with proxy-able variables could be doable.

Or your channel method previously mentioned?

Related, yes, but still different, I'm just thinking about a proxy method between subnetworks/channels.

Possibly related: CyclopsMC/IntegratedTunnels#18

Actually, as I think about this, I can't think of any reason to ever need isolation between Integrated Dynamics networks other than for Integrated Tunnels, so perhaps this issue should be closed in favor of the other one.

Indeed, I'll close this one.

But the actual implementation of subnetworks should still become part of ID.