We are doing pilot testing of an AD migration. It's a fairly straightforward consolidation from source domain to target domain, with a 2-way trust between them.
Users in the source domain also have an active account in the target domain. This was done as part of a previous Office 365 consolidation project, so that all users are in the target O365 tenant, synchronised from the target on-premises AD. Our AD migration is therefore doing a minimal "merge" migration of users, copying SIDHistory but excluding most other attributes.
Most users only log on with their source account to the their Win10 PC which is in the source domain. These users can be migrated with no problems and their user profiles are updated as expected.
The issue occurs when the user has two profile on their PC - one for the account in the source domain and one for the account in the target domain. The default behaviour of RUM when updating the PC is to keep the user profile for the target account and the source user profile seems to be lost. (I have more testing to do here!) In our case, we want to keep the SOURCE account user profile.
Any ideas on how best to proceed with this? We could script something to delete any existing user profile for the target user, prior to processing with RUM. Has anyone come up with a neater solution?