Robert,

It's not required because you can setup credentials that are domain specific.

1. DomainA\discovery
2. DomainB\discovery
3. etc.etc.

If you are able to split out your ranges and schedules to target these domains, I would highly suggest creating multiple MID server instances and relate the individual instances to each Domain credential.

1. Windows Server: MIDSRV
2. 3 installations of MID servers: MIDSRVDomainA & B & C
3. DomainA\discovery is used only by "MIDSRVDomainA"
4. DomainB\discovery is used only by "MIDSRVDomainB"
5. etc.etc.

If you are in the unfortunate boat of intermixing -- DomainB user travels to DomainA office -- then I'd rather suggest ordering your credentials based on who has more computer objects in that domain.