Powering multiple low voltage devices in the truck

and cell phones?
The safest thing to do, which will add more wires, is to power everything off a little inverter.
What happens with modern vehicles is the electronics you have plugged into a DC outlet can talk to the vehicle in some instances. To eliminate this the power inverter seperates the electrical signals so there is no cross talk.
When I say, talk to, I mean the devices put off signals, electrical surges, static, whatever, and the vehicle CPU might read this as a sensor on the vehicle and then do something odd like make minor engine adjustments.

On my previous truck I purchased an add on fuse block with 8 or 10 flat blade fuse slots. I mounted it high up on the insid right kick panel and ran an 8 gage wire to the battery. I added a 30 or 40 amp fuse in the wire near the battery. That gave me plenty of additional power for adding a CB radio, stereo speaker amplifier, cigarette lighter plug for a spot light and circuits for any other 12V DC toys I added.

I have one of these mounted in the inside bottom of the center console:
Power Box
It connects to the 12v aux connector in the console.

And one of these on the top:
Tray

I ran long usb to micro usb or c connectors depending on the device under and through the trim pieces on the console and door jambs. My GPS has a 12v plug which had a long enough cord to allow it to be routed under the trim.
I am running a phone, GPS( the one in the truck is not suitable for towing), TPMS monitor, rear observation monitor, and a dash cam through all this.

I would run some of the items on a dedicated fused circuit straight from the battery and not through the factory fuse block.
GPS, front dash cam and cell phone chargers would be connected to this source.
I am guessing that they are all USB type connection. They would not draw that much!

I have a couple of these installed behind my dash and wired to the fuse box.

I don’t need a rear camera when moving forward. My GPS, when on, is on the dash screen. Neither of our phones needs constant charging.

Moved to Tech Issues forum from Towing.