ANO rules on pilot maintenance for CofA aeroplanes, and LAA for their handful of microlights are not the same as apply the majority of the microlight fleet which are contained in TIL 020 and the BMAA guide to airworthiness procedures. The differences between the rules as apply to Type Approved, Type Accepted and Homebuilt permits are very pertinent - for example that the rules are different between these with regard to who can be trained on them.
For example a microlight with a type approved permit can be used for training of any pilot, whilst with a type accepted or homebuilt permit cannot. In some cases two apparently identical aeroplanes will have different permits.
The rules on NPPL(M) validation are not the same as for NPPL(SSEA) or JAR-PPL(SEP) are also different [5 hours in 13 months, stamp in logbook from a microlight R examiner.]
And that's just a couple of examples.
In my opinion anybody teaching on microlights needs to know this stuff, (a) because it's in the microlight air law exam that their student needs to pass, (b) to avoid inavertently breaking the law themselves whilst teaching or examining, and (c) to maintain some basic credibility with the people they're teaching. Microlight licence privileges are not in the JAR syllabi and there's no reason why they should be.
Basically all I'm saying is that a JAR instructor planning to teach on microlights, aside from getting current on type and knowing the flying syllabus, should have read through a copy of a microlight air law book. Hardly a major imposition. I'd personally recomment Cosgrove, which is really well written and covers the whole NPPL(M) groundschool so you have a good source of reference for anything else and opportunity to check that your understanding of all the other exam topics is as "received wisdom" in the microlight world and so you're teaching approaches that will not cause your students to fail their writtens.
G