Upgrading from 1.2.3, Load Balancer Pool to Gateway Group needs to strip invalid characters
The Load Balancer pools on 1.2.3 had a lot looser restrictions on naming than pf does on 2.0's gateway groups.
For instance, the on 1.2.3 you can setup an LB pool with the name "Wan Fail -> WAN2" so if you upgrade that box to 2.0, the rules will fail to load. To fix it, you would have to edit and save the gateway with a pf-compatible name and then edit all of the rules that used that gateway to use the new name.
So the upgrade code will need to be adjusted to not only strip the invalid characters, but also correct the gateways on the firewall rules. Also need to make sure that we aren't duplicating a gateway name after stripping the invalid characters.