From the reviews Exped looks like a very reliable truck.
My research show there is a chain of events -
2 cent The tensioner seal starts to leak (I believe it is the same part as the older 2V, which never had this problem. They have a machined seal).
tensioner don't keep good tension on the chain, and that can damage the guides
Oil pressure is lowered for the top of the engine, more the right cyl bank
The cam phasers lose pressure and start to destruct.
Then the cam and bearings(Semi circle head surface) get destroyed. There is no cam bearing, so that usually means the head is trashed.
By the time this happens, there is lots of metal in the engine, and it is worth scrap.
There are also problems with the rockers. It isn't the best quality part, combined with low oil pressure, they can self destruct. TSB on every 4.6L/5.4L 3V.
The ford place told me if you do buy the truck and are handy, replace all the rockers, the phasers and maybe the tensioner too if you plan on keeping it a long time. Use ford parts
They also told me to use Pennzoil Platinum ultra 5w-30.
An oil pump helps but it is a bandaid solution.
https://www.motor.com/wp-content/uploads/O-the-Troubles-Ive-Seen-Nov-2013.pdf
https://static.nhtsa.gov/odi/tsbs/2014/SB-10056148-6661.pdf
https://static.nhtsa.gov/odi/tsbs/2018/MC-10143079-9999.pdf