It has recently been noted in the U.S. that Insurance Statistics are showing an increase in LSA ( Light Sport Aircraft ) accidents by more experienced pilots flying these aircraft, than new pilots starting and continuing only on LSA's.
They do need different techniques, and some dual would be an advantage, if not mandatory. One of the biggest differences is in lack of inertia, If you pull the power off over the hedge, they won't continue to glide in like the heavy iron, but will drop out of the sky very quickly.
In NZ, one needs a Microlight Certificate ( not Licence, for some quirk of International nomenclature ) issued by one of the 3 Microlight organisations, but after that the cert. can be kept permanently valid providing that all aspects of the PPL are also valid. The med. standards are as for an aged drivers' licence renewal. If, at age 75, the Dr. will let you drive home - you can fly a Microlight !
Holders of a GA CPL can fly a microlight for hire and reward - if they also have the required M/light cert.
One also needs a regular Radio Licence if one wants to fly into Controlled Airspace, or more than 50 nm from take off point, but there are many Nordo fields on NZ, so many are quite happy to remain within the 50 nm rule.
Sorry I can't answer your question ! just thought you might be interested !