So, I was pretty disappointed when I got my 06 range rover sport and found the window up/down buttons aren't one touch, except the driver's window. I test drove an 07 and it had full one touch window buttons.
Unfortunately, even ordering a switch panel which has double click for the passenger won't make it work. I remember trying that years ago as well...same pet peeve. I never found a solution, but perhaps the guys at GAP IID can confirm if the window can be configured for single touch if you do install the HW.
With P38s and L322s no hardware change is needed. With P38s it was a BeCM setting, L322s through 2009 it was an "owner option" setting in the BCM. I would be surprised if the LR series and Sports didn't have the same optioning during the same time period.