Where kitplanes are concerned, there is no such thing as the EU.
It really is down to individual countries, and if you want to cross borders, what countries will then let you do so.
The UK is restrictive on new types but has a very large list of approved designs through either the LAA or BMAA.
France is generally very relaxed and you can do most things, but don't necessarily believe that you can then fly that aeroplane routinely around the rest of Europe.
G