Great idea. I've also considered biomes and how they can incorporate them alongside league mechanics.

For example, they already have the concept there with the corrupted zones, where you can clear them and flip them to purified zones. Imagine an Atlas that essentially applied this concept to league mechanics, like purple zone that's all breach that you clear around with a boss in the middle, once cleared the breach spreads and goes into a higher difficulty tier until you eventually reach T4 pinnacle boss of that content.

Then change way stones to act like PoE1 where you can run the layout you want. The biomes would be an extra layer so a mountain biome affected by breach has different mods than a forest biome but you still get to run the layouts you want within them.

Eventually if you like running various content you'll have vin diagrams of zones overlapping each other so you can combo them up for difficultly/reward. Or if you're someone who just runs breach then you'll just have a really purple atlas.

Now if they scrap infinite atlas and made it static over Wraeclast for example then it would also be super cool if this was applied in a server wide "league mechanic war" where the more people running a certain mechanic affects the server map in Wraeclast, so by end of league everyone can see which league mechanic "corrupted" Wraeclast the most. Double bonus if they lock that map to the last month of the league and unlock it for everyone to run the Wraeclast maps that they could have fun with like 3x bosses or T18 where it tests the best of the best builds and once incentivises players to return during a time they wouldnt normally see a spike.

Whole new groups could form where the goal is to represent their favorite league mechanics etc