From the decription of your aim, I'm not convinced that SNAC HI results will play any part in the allocation of subnets for your endpoints. Use of the LAN Enforcer will only add checks for if the HI check passed or failed, it will not provide you with geographically dependent VLAN allocations.
Configuration of a different default/production VLAN per switch is entirely possible without the LAN Enforcer, which is why I say this is not really a SNAC question, but more one for your network admins or for Cisco.
What part do you see SNAC playing in this setup?
The reason I ask is that even if the LAN Enforcer was involved, the most likely config would be for it to tell the switch to "open port" on successful HI/Auth/Policy check results, in which case it's down to the switch config to assign the VLAN anyway.