Minimum distance (between ceiling & cabinet) for lighting 1
6? is very close. 12? or over is better. What will happen is that you may be able to clearly see where the lamps stop and start if you have a row of multiple lamps that don’t overlap. The ceiling may seem too bright above the lamps and light won’t project out as well into the room. A light very close to the ceiling will also show more of any ceiling texture which can be bad if there are imperfections. Keeping the light on the softer side will help. You can use a lensed fixture to help diffuse the light.Distance between cabinet and lighting 1
Minimum distance (between ceiling & cabinet) for lighting 2
If the cabinets need to be close to the ceiling it would be best to stay with lower wattage to minimize hot spots.
If your entire kitchen is to be high efficiency lighting then you can use warm color LED above the cabinets for a soft glow. Not all LED is Title 24 approved. Much is not all that efficient for general lighting applications. If you are trying to hide enough fluorescent to get some incandescent then you’ll want to stick with fluorescent on top of the cabinets and lower the cabinets so it looks nicer. There are low profile fixtures available to help hide behind crown molding.