Duplicate on the bed...

BobS

I often will print a single copy of something to tweak it until it is just right...
and THEN go back to the slicer and duplicate 5-6 copies and re-send it to RS.

what I would LIKE is if I have a model I like is to have Repetier duplicate it.

if you know the gantry/hotend clearances you could offer 1 at a time vs all at once (normal)
you could offer "duplicate how many times" or "fill build plate"

there would need to be warnings of retraction setting needing to be set properly and some other settings as well to make it work well

Repetier

That also needs deep understanding of gcode knowing which is start/end code and geometry and a lot more to find positions correctly. So that is quite complicated and error prone after the print generation, so this will not come. 

What you can do is generate full model and exclude the places with your copies from printing or just stop print after first.