t the construction of the headrest Nick? 5mm ply with 50mm of soft foam attached to a steel plate would not meet even basic automotive standards.
It’s cannot possibly make any contribution to safety in a crash. I get you are trying to protect DG, but really, you are putting reputation ahead of safety, a stance that does you he credit at all.
I think you will find In the near future there will be an AN allowing the headrest to be removed. I have in writing the opinion of the most senior experienced airworthiness person in this country,
who has a CASA delegation to approve mods, that there is no legal reason the headrest cannot be removed.
Quote from email:

Your DG200. was certified by the German LBA under “ LFSM 1975 Airworthiness Requirements for Sailplanes and Powered Sailplanes. ” Perusal of that document shows no mention of “Head Rests”. That means it was not needed for Certification. An optional extra if you like.

The current CS22 Design Requirements do have a mandatory fitment of Head Rests with strong emphasis being attached 2 or part of the seat.

We also know that there are findings from accident reports that the original headrest may strike the pilot in the back of the head when the canopy is jettison. When Design Requirements are updated retrospectivity is not applied.

Based on all of the above, you can do what you like with the headrest. Being there, or not being there, has no influence on operations or airworthiness and the increased pilot safety is a key issue.

Pretty conclusive.