As far as RNG is concerned they should probably do away with the ridiculously rare chest spawns anyway. Awful way to grant the player the most powerful equipment in the game.
Aren't those only really obtainable with save scumming anyway?
If you're talking about the invisible chests with the invisible equipment, then yeah, they should be eradicated entirely.
If you're talking about all of the normal equipment you can get in the vanilla version of the game, the Zodiac version already fixes all of that. The vast majority of the high-end equipment is now in one-time 100% spawn/drop chests with only a couple of exceptions.
Edit: Actually not just the high end, but pretty much any piece of equipment found in a chest, and all spells/abilities found in chests as well. Unfortunately, the chest you can open up after defeating the demon wall only holds a Scathe mote now. But it, too, is 100% spawn, 100% drop and never spawns again.
(I've put about 1200 hours into IZJS, so if anyone is curious about anything with it, let me know)