Earlier this week, we posted a news article describing some of the changes to the Atlas of Worlds in the upcoming 3.10.0 expansion. In response to community feedback, we have written a Development Manifesto entry to discuss the concerns you raised. As always, thanks for your timely and passionate feedback.Sustaining Maps
In Conquerors of the Atlas, we dramatically and somewhat inadvertently increased the map drop rate, through the following mechanisms:

• Conqueror influence adding a large amount of monsters and content to Maps when spawned.
  
• Additional maps from Awakening Levels (including Shaper and Elder Guardian maps).
  
• Synthesis Unique Maps dropped by bosses.
  
• Unique Watchstones.
  
• Additional monsters spawned by higher-tier Sextants.
  
• Conqueror maps being opened for "free" by Zana.
  
• The map mod effect from Awakening Levels applying to Quantity and Pack Size modifiers.
  
• Blight going core.
  
• etc.

Even though we did remove Shaper and Elder influence, the number of maps added was a lot higher than the amount we removed. Some of our team members finished the league with a many hundreds of excess tier 14 maps in their stash. Players playing the league commented that Delve cities did not feel rewarding any more (because in the past they were a great source of Maps). Similar comments were made about the Temple of Atzoatl, which was also a good place to find maps in the past. The very easy access to maps in the Conquerors endgame diminished the relative reward earned by running other game content.In addition to the above changes that made maps a lot easier to find, our plan for 3.10.0 was already going to take it even further:

• Improved Temple of Atzoatl
  
• Improved Vaal Side Areas (and they can now drop maps!)
  
• Metamorph going core
  
• Delirium being a high-reward league if you take risks
  
• Being able to tell when Conqueror Influence is about to occur so that you can roll your maps for it to maximise drops

We decided to tweak the Awakening Objectives to remove the bonus to map tiers because it felt unnecessary after replacing it with the Map Mod Effect, and it wasn't really an exciting bonus for most players to work towards.Playing through the Atlas in 3.10.0 will still result in a flood of maps compared to pre-3.9.0 Path of Exile. If you're worried about not being able to sustain maps easily, you needn't be. It feels good in our testing so far, and we will be keeping a very close eye on this.Target-farming Maps and Cartographer's Seals
This is a big topic that we're still discussing internally. Philosophically, we don't like that Cartographer's Seals go against the natural progression of your Atlas. Ideally we'd prefer that things were designed in a way where un-completing maps was not necessary. We want players to earn map completion and bonuses objectives and to feel good about having them. Cartographer's Seals worked directly against this.We have some ideas that we're discussing that should help on this front, and we'll let you know as they progress through internal testing. To be clear, our solution will not involve Cartographer's Seals coming back in the same form they were before.Map Mod Effect
A separate goal in 3.10.0 was to make Awakening Objectives more desirable. As we just discussed, map drops were at an all-time high so we didn't want to add more map drops to Awakening Objectives. Our plan was to move the popular Map Mod Effect increases to the Awakening Objectives in order to give them more of an incentive.You're completely right that Map Mod Effect isn't always positive for every build. For example it can ruin Ignite builds by making it impossible for monsters to be ignited. While map mods are designed to hinder your character, the Map Mod Effect can sometimes push it over a reasonable limit. We will make adjustments to those cases.If there are any other problematic mods other than ailments, please let us know and we'll look at those too.