As we will soon be upon our 5th iteration of Treasure Maps that are likely to remain largely unchanged, I would like to suggest a shift in how RNG is handled in maps that I believe would make them a lot more appealing for all players and offer a breath of fresh air for this content.
As it stands now, the conceit of gaining access to a treasure map dungeon is that fate can kick you out of the content whenever it decides you don't get to play anymore. Obviously nobody likes getting kicked out cause then you aren't getting your loot, but it also just turns a majority of the map experience into 1) traveling to a new location 2) retainer/mogmail juggling for new maps 3) killing the same two sets of mobs just to get a chance at getting back inside.
I would like to propose removing the ability to be kicked out of a dungeon once you are inside to maximize the amount of time spent on the thing that's fun: killing mobs, killing a boss, and getting a loot drop.
To use the current format as an example, instead of RNG deciding you picked the wrong door or landed on an Atomos and kicking you out, I suggest these failure states instead buff the enemies in the dungeon. Conversely, picking the right door or perhaps landing on a favorable space of the wheel grants your party buffs. This creates an environment where your only failure state for the dungeon is whether you can survive each wave, and good or bad luck make it easier or harder to reach the end. The idea is not to change the difficulty, but to give the player the agency to control how long they stay in the dungeon.
At the same time, the RNG must remain in some capacity to ensure that the whole concept of maps isn't changing. So, instead of balancing the rate of getting something cool on whether the game lets you keep playing, we move all the luck into the reward at the end. To compensate for a much higher clear rate, the dungeon should only contain 1 loot coffer at the end which rewards a random amount of standard rewards: crafting mats, materia, gil, tomes, etc.; and possibly a rare unique item or two.
There are some other tweaks that would be needed, but I am curious what people think of this concept.
tldr; Remove RNG removal from Treasure Map Dungeons and replace with random buffs/debuffs. Loot upon completion is balanced accordingly.