In a particular environment all permissions were assigned to Local Groups.
After using RUM all permissions were re-assigned from source Local Groups to Target Local groups.
The behavior with regards to the Local Groups is described in SOL15806
Administrators goal was to convert Local Groups to Global Groups.
He was explained that this is not possible natively so it is not supported.
In this particular scenario the admin was well aware that this is not supported but wanted to proceed.
He found out that he can first convert a Local Group to a Universal Group and then change it to a Global Group.
But this will only work if a group doesn't have any Foreign Security Principals (members from another domain).
Finally he reported he used ADModify to perform this task.
Important: this is not officially supported, the article was created just to share some experience.