I second that.BMW put it on there for a reason. I would NOT take it off. I think they know better then us
It's interesting to hear largely US comments on this, I think. It doesn't seem to be an issue in the UK from what I can make out.
Another aspect that would seriously weigh on my mind is insurance implications. Our insurance industry are as hot as nails for finding ways not to pay out on a claim.
Most insurers will have asked you to state that the bike is in standard condition and not modified. If you tell them what you've done you'd be fine, although they may hike the premium or even decline to quote. On the other hand if you haven't owned up and you are involved in a serious moving vehicle incident, whether your fault or not, the assessors would be over the bike with a fine tooth comb and you could find yourself up sh#t creak without a paddle!