We can only wait for the official response on this one.
My own view, is that Microlights are included in the SEP Class Rating, and that you are only required to carry out 'Differences Training' (and have an Instructor signature in your logbook) if you want to swap between control types.
Any 'Familiarisation Training' you may receive when moving between types with the same control system does not require an Instructor signature. (Unless it has other features requiring 'Differences Training'.)
As you have read, this is not a universal view.
MJ
