The LAPL priviliges state:
FCL.135.A LAPL(A) — Extension of privileges to another class or variant of aeroplane
(a) The privileges of an LAPL(A) shall be limited to the class and variant of aeroplanes or TMG in which the skill test was taken. This limitation may be removed when the pilot has completed in another class the requirements below:
(1) 3 hours of flight instruction, including:
(i) 10 dual take-offs and landings; and
(ii) 10 supervised solo take-offs and landings.
(2) a skill test to demonstrate an adequate level of practical skill in the new class. During this skill test, the applicant shall also demonstrate to the examiner an adequate level of theoretical knowledge for the other class in the following subjects:
(i) Operational procedures;
(ii) Flight performance and planning;
(iii) Aircraft general knowledge.
(b) Before the holder of an LAPL can exercise the privileges of the licence on another variant of aeroplane than the one used for the skill test, the pilot shall undertake differences or familiarisation training. The differences training shall be entered in the pilot’s logbook or equivalent document and signed by the instructor.
I can find no reference in the Regulation to a "Microlight" being any specific Class or Variant of aeroplane! If it is possible to fly the Microlight under the Regulation using a LAPL, then why would one not be able to maintain currency in the same Class or Variant?
In France, neither an EASA PPL nor a LAPL is valid on a Microlight Aeroplane! A seperate licence is required.
From the CAA website:
Regulation (EC) 216/2008 excludes Microlights from European Aviation Safety Agency (EASA) Regulations and so they remain subject to national rules. You will need a UK national licence to fly a microlight in UK airspace.