Atlas tree masteries for mech progression

This is just rough ideas/fantasy I would like, written up. Bit of a long read but maybe it'll be interesting.
This post is specifically targeting GGG's announcement for 3.28 "We are aware of feedback from players that late endgame farming strategies are currently lacking in diversity and progression. We are putting together a list of adjustments to address this, with an emphasis on making currently underperforming strategies more competitive. A larger amount of changes to this area are planned for 3.28."
The main thing I've been thinking about is the 'progression' of the mechanics and my own experiences trying out different strategies and going through them. I like to keep track of my profits specifically so I am not going off purely by feeling either.
Currently very few mechanics have end-game scaling that is comprehensive, often simply results are greater if mechanics are done faster rather than making them more difficult and rewarding.
Take for instance delirium. I have farmed both strategies already speed running with the mirror and farming for deli orbs, then another strategy where I used those deli orbs. Sadly what I hoped would've been the higher level strategy (using the deli orbs) was way less profitable than just spamming mirrors. I was getting to 16 rewards per reward type on every map and the loot was appalling.
Having a look at one of PoE's competitors; Last Epoch. They have incredibly basic mechs right now, however due to corruption being scalable as high as the build allows you creates the sense of progression, you're always getting more rewards for having a stronger character and doing tougher content.
In PoE, on a league starter (99% of the time), if I can do my mechanics on T16 100% quant maps, anything past that makes barely any difference. Save for a few strategies like ambush farms in T17s.
Expedition? big bomba and go, Blight? atlas does not impact your ravaged maps, Deli? Mirror and go, Harvest? Pack size and burn maps, Abyss? tons of monsters, but will they drop anything? I could go on, but overall speed is too rewarding and farming more loot just means your character is clearing the same content doing the same thing over and over just faster.
I feel like there's plenty enough of horizontal progression and variations in mechanics now for us to get a bit of vertical progression in the future which is what I hoped for when I heard that breach is getting a sequel. Alas, barely anything can be done to juice the blood/gifts you obtain and from my testing it's another map burner league mech if you're wanting the loot. A sort of next tier, for the currently available content would be amazing to see and kinda what I'm hoping for. Bossing has normal/uber right? Though I'm joking to explain my point; give us uber mechs.
How this will be implemented is entirely up to GGG, as the idea goes, we know what we want but not how we want it. So, as a little thought exercise and showing through examples I wanted to write what I would try out in a league.
Atlas masteries! as per the title, I thought what better way to become a further specialist in mechanics than having masteries which open up after already investing points into a specific one.
I would probably prefer these to be a bit more costly (5 atlas points) or limited to 1 / 2 choices, as they should be strong, difficult and rewarding specializing into specific content rather than diversifying and cherry picking the atlas tree.
And now for the fun part, my imaginary list of atlas masteries:

Harbinger Emperor: Maps now contain only 1 uber-harbinger, all harbingers that would've spawned add +110% amount of currency shard drops.
Notes: Bigger stronger harby boss, all harbingers (technically) in one area, +10% currency shards, more convenient and satisfying loot explosion. Maybe some limited uniques?

Harvest Forest: Area's inhabitants are harvest monsters, Sacred grove now spawns packs consisting of difficult and rewarding monsters.
Notes: All 'natural' monsters can be harvest ones, while the grove will be a especially difficult encounter. Can increase the difficulty overall too to balance the Harvest mobs across the map.

Expedition Royal crypts: Logbooks now drop corrupted rare with 4 modifiers for each area choice.
Notes: Expedition can be quite tough already but has nothing like blight ravaged maps. Logbooks should be made more difficult and rewarding with this. Maybe guaranteed boss? 5c per logbook is a sad state of affairs for being 'the' expedition goal.

Legion Decorated Warriors: Generals drop their faction's emblems, Generals and officers gain one additional reward. Legion monsters have 50% 'increased' life.
Notes: Something to make generals more wanted and make monsters more juicy difficulty/reward wise (the +1 reward combined with 'Logistical support')

Abyss eye of the world: Abyss monsters have +10% more Quantity for each prior pit. Abyssal magic and rare monsters gain an additional modifier. Rare abyss monsters have 10% to drop a corrupted 5-6 mod abyss jewel.
Notes: The base mobs need to drop more loot, adding additional mods to abyss rare and magic mobs which in turn makes them more rewarding and gives abyss loot gives great opportunity for scaling and doesn't clash with 'Corrupted Gaze'

I could go on, but if you were asked to make masteries for mechanics what would you make? and what do you think in general about scaling mechanics into endgame?