Offensive terraforming in it's current state would get a MASSIVE buff to invader as defender ewar make little to no impact. I should probably be keeping my mouth shut about it, actually as my opponents are the ones with all the assets on Gamma.
It may be too difficult to conceive of offensive uses for Terraforming 2.0 at this time. Aside from the 50 degree limitation I don't think any other details are known about how the new mechanics will work.
So, for the love of GOD, just leave it alone for now. Once you get the Terraforming Mechancis ironed we can try it out on the new test server, and perhaps there discuss locking time as part of BALANCING.
This idea needs to be shelved.