Same FSLogix profile, two domains

Question

Hi!
We're gradually migrating users to a newer domain but as a half-way house will have users using their old domain user accounts on the new domain. I'm trying to implement this with our on-site VDI too which uses FSLogix.
Currently, users on OldDomain and sometimes on NewDomain are using VDI machines that are members of OldDomain.
I'm working on a new VDI Desktop Pool whose desktops are joined to NewDomain but the problem is FSLogix is making new profile folders for my test user accounts from either domain:

OldDomain VDI (i.e. current):
User from OldDomain gets ProfileFolder "Username_SID"
User from NewDomain gets ProfileFolder "Username@NewDomainName_SID"

NewDomain VDI (i.e. testing):
User from OldDomain gets new ProfileFolder "Username@OldDomainName_SID"
User from NewDomain gets new ProfileFolder "Username@_SID"

Our FSLogix was set up for us with the ProfileFolder using just "%username% for both VHD Name Pattern/Matching. The OfficeFolder was set up with SID Directory Name Pattern/Matching both set to "%username%. (Both folders with swap directory name components enabled.)

Is there anything I can do in NewDomain to make it use the existing folders when users move to the Desktop Pool here? (I know there's ultimately going to be a separate issue when they move to user accounts on the NewDomain...!)

Thanks! :-)