microlights
You can fly microlights on a UK PPL. Normal differences training is req'd if say it's a tailwheeler and you haven't any tailwheel time.
But NOT just because its a microlight.
Going to weight-shift from 3-axis, yes, proper training with a microlight instructor is recommended, for hopefully obvious reasons. (avoids half a day out with the undertaker)
The NPPL's privileges are another matter, LASORS has more info.