I suppose the question is, can a microlight be an SEP?
No. A 'microlight' is an Annex 1(e) aircraft. In the case of a 3-axis 'microlight', it falls under the ICAO of an aeroplane:
A power-driven heavier-than-air aircraft, deriving its lift in flight chiefly from aerodynamic reactions on surfaces which remain fixed under given conditions of flight.
So although flight time in Annex 1(e) aircraft is recognised towards the revalidation of an SEP/TMG Class Rating by experience (as may flight time in Art.2(8) 'opt-out' sub-600kg aircraft), dual refresher training with an instructor must be flown either in an EASA aircraft or, if it has been approved for training by the NAA, an Annex 1(a)-(d) aircraft.