Managed to print it at 0.3mm layer height and fit them on VXE Green Lake switches with minimal to no postprocessing. Feels a bit rough, but saved a lot of time. 

A screwdriver can be pushed on the slot to break apart the strings before pushing it on the switches. I also had to shave off a little bit of an edge for 1 keycap on a corner.

On Prusa Slicer I've used sequential printing, but not sure if it's needed.