Both 12 volt outlets in my 07 LTD are powered when the ignition is on or accessory, but I need them hot all the time for cellular and camera battery charging and GPS. Has anybody done this mod?

We did the opposite on a 2001 Ford Expedition we had. Both of its outlets were unswitched, and the wife left the radar detector plugged in many times, draining the battery, so I had a local 4x4 shop re-wire the outlets so they would switch off when the ignition was off. If cost $60 at the time (2001). It was a PITA to jump start that thing in the garage.

I'm sure you could find a reputable shop that could make the mod for you and I understand your need, but personally, I don't ever again want unswitched outlets. But that's just me. ;)