Perguntei a mesma coisa nos fóruns de discussão da Apple e recebi uma resposta lá. Estou postando aqui caso alguém encontre isso e olhe aqui.
De Jason Agress:
If you have access to Apple Remote Desktop, you can create a custom Client Installer that sets a machine to use directory-based authentication. However, if you don't have it, you should be able to use the script I've pasted below. Once you've done this, you will need to create Open Directory groups that correspond to the amount of access you want a given user to have (ard_admin, ard_reports, ard_manage, ard_interact) and add users to the appropriate groups.
#!/bin/sh
sudo /System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Resources/kickstart -configure -clientopts -setdirlogins -dirlogins yes
sudo /System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Resources/kickstart -restart -agent -console