Jan,
I don't agree that the exemption excludes all microlights. Homebuilt microlights are exempted in my view, in spite of EFLEVA's email stating "For ultralights the existing procedures and regulations remain in effect."
I can't get links to the Royal Decrees of 8 June 2017 and 16 March 2009 to work, but you will know how to find them.
Have I misread something?