[Merlin66 (Ken)]

I have the C11 sitting on the NEQ6PRO on a similar pier.
I added the standard 200mm extension to the top, uses a 12 x 1.75mm stud to fix to the top of the pier.
The NEQ6PRO head just fits as usual to the top of the extension.
No cage etc, works very well, no real issues, no drama.