Unfortunytely I got another one

--how does the terraforming tech work? Example:
When I create an Orbital Terraforming Tech and an improvement along(Gaia Terraformer, s_type normal, PlacementLimit 1), the PlanetaryQualityBonus(set to 100) has no effect on PQ, would it theoretically apply with EnhanceLevel=4?
Why does it have an effect on the other 3 tech, is it only active with (or realated to) the EnhanceLevel tag? Is the EnhanceLevel capped to 3, otherwise one could make a new "darkred" tile?
Despite my Questions,Questions,Questions ...
Thanks for the quick reply