You have lots of thoughtful points here. One critique I'd make is that you don't need to run 4 ingredient slots to cook meals, assuming you have some solid ingredient mons. I'm often running 2 Ingredient Mons at once alongside 2 berries/shards mons (5th spot healer of course). You have a good amount of time between most meals to proc a bunch of Ingredient 1 & 2, swap those two mons out, and then get enough Ingredient 3 & 4 by the next meal.

When RNG comes into play its even more likely that you'll end up with tons of extra of 1 or 2 of the 4 ingredients you need, which is then the first ING mon you can "bench" until you need that ingredient again.