Im guessing if the company that widened them didn't do or offer to do it they must believe it wouldn't be a good idea. It does appear that they welded on both sides of the wheel, so it may be ok. What does the wheel company have to say about grinding the welds?
if he had them done by weldcraft then i would think it was ok cause they offer to widen the lip and smooth the welds and refinish the wheel for more $$$ i think they dont ask anyone if they want the inner ones smoothed cuase they assume the people wont care??? i guess...
like anthony said thought best to just give them a call and ask.