Actually I have a current CAA (M) licence which I use to fly a group Eurostar microlight. I also have a lapsed NPPL (SSEA) which I have considered revalidating as I would like to buy a Star Streak or Streak Shadow. I will be happy to revalidate if the single existing medical will be retained and I won't be forced to have two medicals.
Of course I could just buy a microlight version of the Shadow but I felt that the NPPL SSEA would open up more opportunities.