Tried this mod first. Lowest part of gimbal to desk is 3/4 inches. Had to remove because it makes landings too difficult on hard surfaces. On the slightest rough landing, these act like springs, and bounce the quad back into air. It then flips over and crashes upside down. Removed after a couple of batteries thru.
Try two. The lite-foam pipe-insulation seems like a good material to get some height. Lowest part of gimbal to desk is now 7/8 inches (so a little better). I would prefer it to be stiffer, but it's not too bad. Notice it's 2 layers thick (but only on bottom for max. height). Inside layer is not complete tube/circle and is tie strapped to LG first (to prevent slippage). Black rubber bumpers are not needed and saves 13 grams. Will try it for a few flights.
Only cons are ... it will bounce/flip on hard landing and ... foam surface catches wind (rocks gear?).
Well, I think I found the best way to mod the stock white plastic landing gear for use with 2D gimbal. These will raise the lowest point of the gimbal to 7/8 inches or 23 mm ... as high (or better) as foam, but without the surface area (acts as sail in wind) and springy-ness.
HK now has Extended Rubber Feet for Landing Gear Skids -
Fits Quanum Nova and Cheerson CX-20.