Transition 'height' - now, there's a new one.
Nothing to stop you flying IFR if you like, even if you don't have any instrument qualification, as long as you maintain VMC.
Apart from European law, that is:
FCL.600 IR
Operations under IFR on an aeroplane, helicopter, airship or powered-lift aircraft shall only be conducted by holders of a PPL, CPL, MPL and ATPL with an IR appropriate to the category of aircraft or when undergoing skill testing or dual instruction.
In any case, just because you choose to fly at a quadrantal level, it doesn't necessarily mean that you are operating under IFR.