@po18guy I wasn't pulling you up over the "IF" that was not my intention I apologise if you thought I was, it's just this scenario has been suggested before, I have written a full explanation before on this forum. and before posting looked for it in the search so I could just add a link to it, but after a 30 mins search could not find it, perhaps it buried within some other thread, so I made a simple cut down version in reply, having done this very mod to the gen 2, (first tried on the gen 1) it's not as simple as it may seem from a "what if" idea, possible of course it is, but far more involved than just swapping out the top yolk.
to be honest it's not really something members from North America (and other places) should consider if the ER5/500 is not one of their country models you need so many parts from the ER it would make the cost (especially shipping) prohibitive just to alter the bikes handlebars.