Differences training, as specified in ANO Schedule 7 Part B Section 2 must be completed.
I agree. That is the law.
So what is that differences training? Well, it depends on what you have flown.
Here is ANOs7B2, my comments in between *s
If the aeroplane *that you - as a light aircraft pilot - want to fly* has:
(aa) three axis controls and the holder's previous training and experience has only been in an aeroplane with flexwing/weightshift controls *ie NOT a light aircraft since I don't know of any flexwing/weighshift light aircraft, but let's make a rule in case there are future development!*;
(bb) flexwing/weightshift controls *ie a "traditional"microlight* and the holder's previous training and experience has only been in an aeroplane with three axis controls *ie all light aircraft and, maybe, a Fairey Rotordyne or some such obscure thingy*; or
(cc) more than one engine, *but the only microlight with more than one engine is the Lazair, which is a single seater, so what is the training?!*
before exercising the privileges of the rating the holder must complete appropriate differences training.
So, we know that aa and cc don't apply, since there are no weightshift light aircraft and no two-seat twins you can go dual on. (Or if it is a twin, you need an hour in the classroom and then off you go in your Lazair, or possibly Eagle.)
That leaves bb.
This only applies if you want to fly "flexwing/weighshift"
So, if you want to fly three-axis microlights, it doesn't apply. And neither does aa or cc.
Therefore, no differences required by law for light aircraft to 3-axis microlight under the ANO.
Pretty cut-and-dried.
The big issue is with aircraft like the Eagle, which is neither (or both) weighshift and traditional! I suppose since it has partial weightshift controls it is covered by bb? But then there are no two-seat Eagles!