Can't agree more!

You can do a simple string test as well to check if you are getting coolant in the cylinders. Let the engine stand over night and then remove the spark plugs for the affected cylinders, insert a piece of string long enough to reach the piston. If there is any coolant in there the string will come out wet. The spark plug will also look like it is steam cleaned.
What did James say?

Let me clarify - I have the truck parked at this time and I was in my other vehicle when I stopped by the shop on Sat. It was more for introducing myself but I did describe the symptoms. I’ll likely bring the truck over some time this week so that James can take a good look. The biggest concern is a possible slipped cylinder sleeve …

A slipped liner will make a lot of noise once the engine is warmed up, but not leaks like that. The liners are not wet, meaning the coolant does not touch the liners. So even if you had a slipped liner then you would not necessarily have a coolant leak. If you had a crack in the block behind the liner then you could get a coolant leak, but they is getting way ahead of your problem. I think you have a plain head gasket leak IMO based on the information given, but without seeing a vehicle it is just a best guess.

After letting the truck sit for a few days I took her to work this morning (after filling up the coolant reservoir, of course) and on cold start there was definitely a lot of white smoke coming out of the tailpipe, smelling like coolant also. Looks like water is definitely getting into some of the cylinders. Interesting that it wasn't misfiring though. Still running well after warm-up. I will be taking the truck to British 4x4 for James to look at in an hr.

Bad news - James took the spark plug out of cylinder #4 and the inside looked wet. He explained that the water jackets are at the front and rear of the banks and for cylinder 4 to get wet a slipped sleeve is the most likely cause. If I’m going ahead with the repair it’s going to be a used or new engine…