I wonder if there is an after market Chain or Belted Chain kit that can be used to replace the belt system ? .. Who wants to replace a Belt every 100km ? .. It might be understandable if the water pump was not so good because Toyota typically replaced both chain and water pump at the same time in my other Toyota vehicles .. This was true for my 1981 Celica strait 6 and my wife's Late model Camary belted chain v4 ..Automatics are superior off-road for the same reasons trucks and heavy equipment use them. Power is converted to torque at low speeds and heavy loads.
The timing belt is a serious failure point. When it goes it is catastrophic. Every valve will bend and you will need new heads, possibly a piston or 2, hopefully that's it.
For driveability the 1HD-T is a dog on the highway if you have an armoured up trail rig. Don't even think about passing a tractor-trailer without a five-mile window. RHD is a PITA and the diesel just makes it more so. Great for offf-roading. For Expeditions not so much.
Most parts need to come from Australia so expect to pay those crazy shipping costs for everything.
My experience anyway. FWIW