For bikes with type approved lighting (not sure of the date, outside my area of imeadiate knowledge), ie those without a switch, whatever comes on with the ignition would have to work. Strictly speaking, if approved with filament lamps LED's probably do not meet the requirement.

Bikes before the lighting approval are covered by national legislation. Typically this will state something like "Dipped headlight on at all times" which will be further defined in national construction and use type regs as having a certain beam pattern. An LED inside the headlight shell might meet this but the strips won't. You could make a fair claim that the strips are a marker or sidelight, so if thats what the other countries law translates as you have half a case.

The Plod is never going to be able to test any of this. The likes of MIRA and the TUV's have tilt ramps and back lighting and screens and meters and lasers and goodness knows what else. The Plod will do it by eye. If they can see your light and it's white and looks like any other bike they'll assume it's close enough. If you dazzle or can't be seen or the pattern of lights may confuse an hungover 12 year old with a license to shoot people, they'll write you a ticket. There is the additional factor that ticketing foreign bikes in places without on the spot fines is often pointless, plus what's legal on a UK bike in the UK is legal for transit through any UN country even if local law enforcement disagrees. Law enforcement have the additional fall back that modified lights also equals no insurance and you were probably speeding and had bald tyres as well.

It's a can of worms. If the LED's will save your battery (check, on the Enfield it certainly used to be use it or loose it), I'd look for something that looks closer to standard bike lighting (spots with LED H3's?). If you don't wake the Plod up you avoid all the issues above.

Andy