A small correction Justicair - VLA category aeroplanes can be "certified" by every standard you might wish to apply, they can be used for training, hire, tourist flights - you name it. Many VLA aeroplanes have an EASA CofA (that many LAA aeroplanes are also VLA is because manufacturers choose to go the kit route, which is the main reason CofA then becomes impossible for that airframe.)
It just that VLA (which was actually based upon BCAR Section S, the UK's microlight regulations) is a low-cost simplified certification standard which limits aeroplanes to day-VFR, it is also limited to fixed gear 1 or 2 seat aeroplanes with an MTOW not above 750kg. That could, for example, be a C152!
Interestingly, the FAA who accept VLA (despite it being a European requirement), created their own bolt-on to allow a bit of additional certification to permit night and IMC. This seems to work fine over there so a DA40, a European aeroplane, for example, can be flown IMC on the N-reg, but not on the G/F/D/etc. registrations.
This is cost effective in the USA because CS.VLA+bolt-on is still much less complex than CS/FAR-23 which is the normal certification standard for light aeroplanes; part 23 is designed for aircraft up to about 5700kg, including multi-engine, pressurised, retractable - and that all escalates the cost and complexity.
I don't think anybody has tried, but I suspect strongly that if you took to EASA a certification proposal of the FAA method of CS.VLS + bolt-on, for a basic 2-seater certified for night and IMC, they'd probably accept it with some work. It would just take a damned good certification engineer to make the case, and I'm not sure than any of the European little aeroplane manufacturers (a few of whom do employ engineers that good) have either tried, or realised that they could.
G