i think he wants to do it the other way around
Learning in GA and then convert.
In fact i found once i had got over been scared s***less in the microlight in A strong wind i was doing a better job than in the Cessna, Facing side ways in a crosswind due to the lower speeds ,is a bit like been a flight engineer , ??
Or indeed learn Microlight and add SSEA ,as they say,and then your,12 hour in 24 months can be cross-credited as long as you have at least 1 hour on each type and 1 dual, included in the totall requirements