Mega-Dungeon Idea

Hello! First time poster here. Thought I'd share this idea which came to mind when chatting to some FC mates.

Mega-Dungeons: Designed like a real place that can be explored, so not just linear hallways. The length of 3-5 dungeons depending on the story etc.

Key features would be the following:
-Split into "wings" for Duty Finder. As you progress through, you unlock additional wings (like in the Normal Raid series). This helps make running it more manageable for PUGs due to the reduced time commitment.

-For premade parties, the whole dungeon is available to explore, but you have save points similar to Deep Dungeons (maybe after each boss or x number of bosses?). This way, as a premade, you can explore to your heart's content, but also not feel compelled to complete it all in one sitting.

-Variable difficulty (so an easy mode for those who just want to focus on the story, with higher difficulties having things like traps, more puzzles, tougher trash pulls etc). Probably three difficulties to cover an easy mode, advanced and savage?

-Have non-combat things such as puzzles, traps etc to be solved in order to progress.

-Ensure there's things to explore, but also rewards for exploring (eg. fancy crafting ingredient, bonus tomestones etc).

I see it as an evolution of the Deep Dungeons - being more of a crafted experience rather than randomly generated floors. Having the wings / save points I think is key to making it work, as not everyone is gonna be able to simply block out 3 hours or whatever to do the whole thing in one go.

I could also imagine something like this being used as an epic finale for an MSQ - eg. you gotta storm the villain's castle, sneaking in through a secret passage, then navigating through the different floors etc until you reach the hidden chamber at the top of the castle where our big bad guy is summoning demons or whatever.