the regulations for France are easier for microlights I believe. The required equipment fit (transponders?) is less in some cases.
I am not aware of any country with an absolute requirement for a transponder in a microlight/ultralight. In Italy you need one to qualify as an "avanzato", without one you'll be a "basico" and thus limited to 500' AGL - 1000' in the weekend - theoretically. German FIS were surprised when I told them I flew without a transponder, but did not object. And Dutch airspace is (almost) one big TMZ from 1200' upwards.