Get-DbaDbRoleMember unrolls nested role memberships

[js-adams]

I found that Get-DbaDbRoleMember is "unrolling" nested role memberships. For example if UserA is a member of Role1, and Role1 is a member of Role2, then Get-DbaDbRoleMember will return both an object for User1 in Role1 and an object for User1 in Role2.

I'm trying to use this command as part of a script to copy over select users between databases, and ensure that role assignments are exactly matched (a requirement for a 3rd-party application utility that performs an app upgrade and data migration). Since the nested role memberships are being unrolled, using the output from Get-DbaDbRoleMemberships from the source database to drive Add-DbaDbRoleMember on the target results in extra explicit role memberships.

Is this unrolling behavior intended? If so, I'm open to suggestions on how to get database users' explicit role memberships.