Is it somehow possible to have the uid field in cn=users,cn=compat,dc=accnix,dc=infrabel,dc=be without the domain extension?

It is causing problems for AD users using an IPA-AD trust

This problem was also discussed in 
https://lists.fedorahosted.org/archives/list/freeipa-users@lists.fedorahosted.org/thread/H6LLSWTXJ3KGERZ6DZFCA4KNQMGLEEOH/

Sincerely 
Pieter