Should be configurable through Settings → VLAN settings.
a) Router IP and subnet per VLAN (Router IP for Default/Native VLAN 1 corresponds to Router’s IP address on the network?)
b) Reserved IP and Pool size.
Pool size is reflected by changes in the subnet but can also be changed separately, though I don’t know how that works with respect to the subnet.
Edit:
Or, Route10 IP setting may possibly be part of LAN subnet selection in the initial setup process, and if so, Route10 firmware version 1.3z or later is required. So I guess it might not be possible until Route10 have been updated as it is a rather recent update and not very likely to be included fresh out of the box yet.