Print objects one at a time.
Prusa slicer allows you to print objects one at a time, which seems to me a sensible way to do things, provided there is room on the bed to avoid collisions.
Can this be done with repetier?
You can send such code, but for slicing you need to do it on the slicer directly. From host this is not possible. Also be aware that is a potential dangerous function especially with bigger objects.