There are several bits of guidance on the Internet regarding pathways to run antenna cables into the main cab. Some suggestions include opening the large bundle of cables coming through the firewall beneath the dash on the driver’s side. Alternatives include slicing into the gromet directly adjacent to this cable bundle.
After dropping enough $$$ on this vehicle to buy a modest home, there’s NO WAY a non-Ford technician will be allowed to touch that.
I’ve found “A Better Way ™”! We’re dealing specifically with a 2023 14th generation 75th anniversary F-150 in King Ranch trim. All F-150s will have a vent trim on both sides of the vehicle and they can be removed fairly easily with a trim tool.
Once removed you can look inside for a factory painted gromet that’s easy to remove.
Using a wire coat hanger and a flashlight you can fish the cabling through this vent hole and emerge beneath the glove box on the passenger side of the vehicle.
(Be sure to wrap and seal your cables to prevent unwanted airflow and road noise and protect your cabling from fraying.)
This venting space provides direct access to the engine compartment. Here we are viewing that venting space from the passenger side, beneath the hood.
Inside the vehicle we again utilize a trim tool to expose the runners which have a large cabling tray beneath them.
I’ve taken advantage of that fact to run cabling to my Anina antenna, mounted on the lip edge of the vehicles’ hood.