But from the CAA web page on microlights:
"A microlight is an aeroplane designed to carry either one person or two people (and not more) and which has a maximum total weight authorised (MTWA) not exceeding:
300 kg for a single seat landplane.
390 kg for a single seat landplane for which a UK Permit to Fly or Certificate of Airworthiness was in force prior to 1 January 2003
450 kg for a two seat landplane
330 kg for a single seat amphibian or floatplane
495 kg for a two seat amphibian or floatplane
A microlight must also have either a wing loading at the maximum weight authorised not exceeding 25 kg per square metre or a stalling speed at the maximum weight authorised not exceeding 35 knots calibrated speed.
All UK registered aeroplanes falling within these parameters are Microlight aeroplanes."
Regarding the part in bold ("either/or") -
*Stall speed (according to the manual which I found on the Internet) of 39kts with 40 degrees of flaps, obviously greater with wings clean.
*wing loading - wing surface area is 9.98m2. At max weight of 450kg, makes it roughly 45kg per m2.
Does this not convince you, from a legal/technical standpoint, that the CTSW is not in fact a microlight?