There are slots, not holes in the footpads, and I believe they will accommodate everything from a 6" to a 7.5" spacing. I cannot guarantee it, but I would be very surprised if they didn't fit anything Naish has made reasonably recently.
The problem with Ntity vario pads is exactly the slots.
The pads are not designed to be used for inserts but rather for rails...
These slots are not parallel and the stance options are limited.