I would put money on the fact that they cannot make anyone who does not reside in Turkey join a Health care system when you can still get UK HEalth Care because as soon as you land back in the UK with a permanent address there you are entitled to UK Health care again. Most Health services in the UK do not adhere to the 3 month rule and in fact we have heard that it's 6 months now or going to be very soon. Also if people come here on a 3/6 month holiday, whilst holding a RP (because of the 90/180 visa ), then they would have travel insurance to cover them which would have been issued in the UK (because that's where you still reside)?