Touring tires and fixing flats
Questions related to ease of mounting can be nebulous to answer, because usually much more than any other factor, what determines how difficult a tire is to mount is the tolerances of the rim and tire. The most difficult mounting situations occur when the bead seat diameter of the rim happens to run large, and the bead diameter of the tire runs small.
There are some known models to avoid if mounting ease is a priority, but there is no totally reliable way to buy a tire that's easy to mount, because tolerance problems can strike randomly. Light, supple tires  mount easier on average, but it's not a guarantee.
Some highly flat-protected tires are notorious for being difficult to mount. As pointed out in the comments, the Schwalbe Marathon Plus has become a poster child for this. The reason is that, especially in narrower sizes, the massive amount of casing armor makes it difficult to get the beads sunk in to the rim well so that the section of tire 180 degrees away can be pushed over the rim and seated. They're also stiff and can be hard to even wrangle the first bead on.
I think that as long as you have still have the ability to reinstall the tire when needed, using a bead jack if necessary, it makes more sense to just choose something tough enough for the roads you'll encounter and the loads you'll be carrying. Unless it's thorns/goatheads/cacti/etc you're worried about, the stuff that gives you flats in a lot of flat-prone areas can also damage or destroy tires. Undergunning it carries the risk of a tire getting sliced instead of simply punctured, which is the kind of damage that the overbuilt casings of proper touring tires are good at mitigating.
If you do want to have some insurance against punctures that won't make any difference in mounting difficulty, you could also use tubes with sealant in them. Sealant has downsides, but can work well in areas plagued by thorns and goatheads, and makes a little more sense in an event ride type context than day-in, day-out.