I truly love this game and this could become a game which satisfies multiple gaming desires

I want to like this idea, a lot. There are some really serious issues, though.

1. Plarium produces gacha games wherein they let you play for free, but it's designed for fomo and pressure to purchase resources (how they make their money).  Any game mode they create must always result in a payout for them.

2. Game design has to feed into #1.  While exploration seems like a great idea, they already have that...it's called Grim Forest.  That only took a few rotations for it to become just another farming chore.  I love GF, but my account is at the right level.  Higher level players find it easy, lower level players find it frustrating.

3. To Diablo or to Zelda?  Diablo thrives off of repeated dungeon crawls to get elite artifacts, and at least boasts some scaling through its difficulty levels.  Zelda on the other hand only lets loose with special stuff one time through, with little replay value.  Given the cyclical nature of Raid, it's likely they'd pick the Diablo method so that people would come back to it repeatedly.  Only problem...clans and clusters would divide and conquer till they find the "Pit" or "Mephisto"-worthy levels that have the best rewards for min/max replay value.  95% of all content would then not get played at all.  If it's not driving people to profit making centers enough to do that development activity, it's a completely wasted effort.

4. Game design has to pick a level.  GF ended up being too easy to harvest Mercurial gear.  While that's not a huge issue from just getting gear, it was in this case because Mercurial was too unbalanced.  And that's the rub.  Make it challenging enough for higher level players, they get accused of whale content (ie. recent proving grounds and the most recent expansion that I don't remember the name.)  Make it too easy, none of the end-game folks bother.

5. Game design takes $$$.  For all the charges we make against Plarium being all greedy and boneheaded, the reality is they spend a ton of money trying to improve the game they made.  They add new content, some of it well-received, a lot of it contentious.  Any new endeavor is a financial bet that can backfire, so they have to have a pretty good idea it will be successful at generating money to make the investment worthwhile.

6. Competition.  Elden Ring, Zelda, Elder Scrolls, Diablo, Final Fantasy, Pokemon, etc. there are so many exploration apps out there, if you want to explore, you'll likely find a better version of it already out there.  Plarium does gacha really well, for all of its warts, but it's not a Blizzard Games or Bethesda type operation.  I have  a hard time believing they'd pull that off in a way that made it worth it.

7. Multiple platforms.  Because it's a PC game that has such a developed phone-based mobile option, such an implementation of overworld adventure in 3D would have a real headache working on a mobile device.  GF is limited in the way it is because it works with a touch screen in an engaging way.  I often play it half the time on mobile, and it's a great implementation.  They could design something that requires a computer-only with a keypad and mouse to enter, but then the mobile players would scream that there wasn't a mobile version.  And that's a real problem I don't see a way to work around.  So many adventure games don't do a non-PC version because it would be too hard to implement with touch screens on a phone.

So I like the idea on the surface, but man that would be a hard, hard ask for a gacha company to bring that to fruition, and a huge financial risk.  Might as well just make a new GF and call it Dark Caverns or something like that.  Then they have to create nothing new, and people have the option to participate or not without development of an entire new game stapled to the existing one.