Let's address the Elephant in the Diadem.

[Seraphor]

I'm surprised that diadem lacks the use of many of the gatherer's special abilitys. We don't collectible anything. There are no uses for anything besides Bountiful Harvest/Yield II or King's Yield II / Blessed Harvest II. \\
Ageless Words and solid reason are useless. You can't use pick clean. The Giving Land/Mind of the Mountaineer is useless. Brunt Force/Deep Vigor is useless. Luck of the Pioneer/Mountaineer too. Diadem is an environment that focuses on a single thing that that breeds cause for depravity. Its a sleep deprivation contest.

Obvious health issues aside, this bothered me as well.
There's literally no reason to meld for Gathering, so you go full GP and Perception and just stick to the Perception route.

What I think they should have done is fix the gathering rate for the 2 star lvl 80 mats in the fifth slot, so that 100% gathering rate is only achievable with a full set of Aesthete that's fully melded for Gathering. Scaled so that someone with no Gathering melded in full Aesthete would be hitting ~80%.
This would provide some valid reason for choosing between Gathering, Perception, or both, and result in rarer Artisanal mats that actually make a profit on the MB, while warranting the use of at least your gathering rate boosting skills.

In addition, have HQ have an effect in some way, even if landing a 'HQ hit' on a gathering attempt does something like, increase the Auger gauge by twice as much.

[Shadygrove]

Stuff

With full iL490s I am melded to 2705 gathering, 2643 perception, 866 GPs. Add HQ peppered popotoes, Gathering +38 & +50 GPs and I am above the minimums for every gathering buff in the Diadem.

Stats for max node bonuses:
Gathering 2740, Perception 2642, GP 858.

Seeing as 858 GPs is trivial in iL490s one needn't meld to my specs as there is HQ mushroom saute for gathering +76 & perception +38.