Can I configure DirSync NOT to rename existing accounts? I want DirSync to ONLY update users passwords and group memberships, and clone new users, but NOT to rename existing users whose target names are different from the source

Hello, I used a regular migration session to clone source users to target, and some of the source users were renamed on target. Some users on the source domain were named with FirstInitialLastName and were created on target with the new naming convention, First.Last.

I turned on Dirsync after migration to sync user IDs from source to target (the requirement was to keep group memberships and passwords in sync) but I have not configured dirsync to skip any attributes, and did not enable target to source sync.

I noticed that the users whose IDs were renamed during the initial migration are now renamed on target to match their original source user ID (firstinitiallastname). 

How can I configure DirSync to leave existing users alone and NOT rename them, while still syncing their passwords and group memberships?  I can exclude sAMAccountName and name attributes from syncing but that would prevent new user creation since they are essential naming attributes. 

I am running QMMAD 8.15

Any pointers are greatly appreciated

Thank you