slugwalk
Chieftain
Terraforming is a level 4 tech. If the problem is in the early game, then giving extra boni to the Terraforming civic won't help.
Terraforming happens fairly early in the game if you head straight for it. Magtubes happen a fair amount later then. Also, even if Terraformers got a +1 bonus to magtube speed, that's still slower than a dropship with movement upgrades (that you tend to get before magtubes).
I also feel that Fungal blooms should happen less in the early game, but that's a separate issue.