In my view, #; would be handy:  #+(or) trips me up visually and is an idiom. I would rather remember that #; is a nulled/commented out form (like ; is for lines),

and reserve #+(or) for connoting other things.

I would not be horrified if it did not get implemented, but I think I would be prone to use it. 

I don't remember seeing a reference implementation link.

I would like to experiment with using one if it exists.