When you meet any of the people in Brussels, you find most of them are former employees of the national CAAs, who were attracted by the fantastic Brussels expense account gravy train, and are now making the best of it.
Turkeys will never vote for xmas.
What has happened to the FAA-EASA mutual STC recognition treaty? Not to mention all the other treaties between the FAA and the individual countries in Europe; these are still valid and operating as far as the FAA is concerned.
If a manufacturer is not going for an FAA STC first, they better have a good reason because some 90% of the GA market is out there.