To get a accurate height measurement you should start from the center of the wheel to the lip of the fender well. I learned this when lowering my Explorer ST and was informed by someone on a different forum. This is relevant for both lowering and lifting a vehicle. Below is more information on...
I sure if enough people inquire to Long Range America, and they can get someone to donate their vehicle for some time so they can protype it, they will make a large capacity tank.
https://longrangeamerica.com/
Congrats on getting your GX.
I am still interested what the hood looks like under the insulation. I really think some sound deadening under there will stop the hood flutters.