I teach SEP for PPL and LAPL. A while ago I got checked out to fly our microlight school's C42, purely for fun and my own pleasure. This involved a checkout and logbook signing by the CFI of the microlight school, which under UK CAA rules is all I need to be able to fly a microlight on my Part-FCL licence. Now, apparently, I can also instruct on microlights on the same basis.
I bought the microlight syllabus out of interest and it seemed to me that although 'flying is flying' there is sufficient detailed difference between how I was taught to teach and some aspects of microlight learning. I discussed this with a couple of microlight instructors and came to the conclusion that if I was going to teach on microlights, to be fair to the students, I ought to go off and do the microlight instructor course, which I've neither the time, money or inclination to do.
So, short answer, my advice would be to go and do the microlight instructor course, whatever the legalities in different places.
TOO