That is not what I stated at all. Would you care to reference that? What I said is that Gavita attaches the ballast directly to the reflector to eliminate RFI.As you stated gavita attached the ballast to the fixture to increase output. The longer the run of cord the less efficient. They also say maximum length from ballast so that tells you shorter is better if they won't run if to long. Please test it. Also test making your own cables out of 2 sizes up wires.
Bigger wires? I've been doing electronic/electrical work for years in a professional capacity. The cable sizes supplied by the manufacturers are just fine and no advantage will be realized by using larger cables. If bigger cables made for higher output, commercial growers would be all over it.