Hey, I am glad you like it.
Agricultural towers quality only affects health, this is based on game engine and cannot be changed with modding.
But I created the Zen-tower-mk2 just for this occasion. Not only does it have a huge area, it plants on a 2x2 grid instead of normal 3x3 and can be used on Gleba as well.
The Gear-garden and other decorative-s pollution consumption is fix, quality will affect their health and crafting speed, but the crafting speed is only there to consume water (bonsai/gear garden).
The Zen-garden on the other hand, gets a nice speed bonus, and is affected by beacons as well. While quality doesn't affect it's pollution, a Zen-garden working on max speed with 15 speed module beacons can neutralize ~200 pollution / min, which is the endgame Biolab pollution. Check Atlantis lake rehabilitation center in the screenshots.
If you have any other feedback, please feel free, the mod has active support.