The documentation for updating firmware states:

Looking for folks that use APEs across multiple domains if this is really true, or whether we can just set up a central share that can be accessed with some jiggery-pokery on firewall rules and pre-loading of domains via the 'hosts ' file?
Alternatively, if SolarWInds allows it, we could just access the share as an IP e.g. \\10.20.30.40\upgrades