That is odd but to be honest, it may be different with an amateur-built airframe. Other options: contact
https://www.vlaamseamateurvliegtuigbouw.be/ or
https://www.nvav.nl/ (you could also try AOPA) and ask them how this works for an amateur-built type. Next thing I would do is look for owners clubs online (there appears to be one on Facebook and I found several other sites). You could also try the EAA and ask if they know of anybody who could help you.