Empty layers - export gcode anyway  

RE: Empty layers - export gcode anyway

You have to enable supports.

RE: Empty layers - export gcode anyway

PrusaSlicer (and most other slicers out there) are designed to provide printer-ready gcode files. A gcode file with empty layers in the middle are not printer-ready. If you really need those gaps you have a couple options depending if you need the top/bottom layers on either side of the gap. Both techniques rely on the default operation of the Prusa provided profiles that add a comment into the gcode at the beginning of each layer with the layer number. With both techniques you will need to take note of the layer numbers at the start and stop of where you want the gap and then in a text editor delete the gcode between those layer numbers so you can insert your own stuff.

The first technique if you want the top/bottom layers either side of the gap, use support enforcers to have PrusaSlicer generate the top/bottom layers and put something in the gap (which you will subsequently manually delete).

The second technique if you don't want the top/bottom layers either side of the gap so you can access the inside (either the infill or emptyness if you aren't using infill). In PrusaSlicer add a box (or slab) part to your object, scale it and move it to intersect your entire object taking up the entire volume of where you want your gap. Don't bother to have PrusaSlicer to generate supports for the box's overhangs as it would be much harder to remove those. Note, this won't work if you have supports for parts of your model above your gap that start the supports below the gap because you will be removing the supports on the gap layers as well when you manually delete your gap.

Hope this helps your custom techniques. (Note, all of the above is theoretical. I've never needed nor attempted to do this so there might be some gotchas that I haven't thought through.)