So... about those nifty new things added...
Not to sound rude or anything, and please excuse my ignorance, but may I ask why?
Just testing it on SP didn't seem to affect any of the non-native terrain blocks. And the structure blocks only got a grass seed treatment with the occasional new random crop growing.
Bit of technical info: The Terraformer can only work a max of 1000 blocks at a time. Costing 5k Essence each and taking roughly 5-10 min per session. It does not need to be moved after each session, but I don't know how it calculates which blocks it works on. I can assume it does a range of 500 blocks to the right and left, and adding 500 more each session, but "ain't no body got time for dat" to measure it all out.
As for a "griefing tool" In my opinion, it would seem rather backwards to use. Its really a cosmetic tool than anything else. Strangers cant place down things on claimed planets. And a personal world's location tends to be a closely kept secret. And if someone happens to have terraformed your home, it can always be undone with another terraformer.
Hello Artaxerxes, the exact look of a terraformed place cannot be restored without using a backup file to before it was terraformed. As for essence cost, people can just spawn in tons of essence and start using them. We've witnessed first hand in our 1.2.0 test server before moving to the main server; that people are willing to fight over terraformers and change the land continuously. Don't forget that once it reaches the planet icon on the terraformer, you change the entire planet with it.
Also, to my knowledge; I'm not sure if terraformers are actually blocked in planet protection yet, as according to the StarryPy3k devs; they're still working on sorting this out.
This block is mainly put in place, because of places like New Haven; where people typically get added a lot to the build list, and we could always have some troll come in and change it; making it impossible to change back without using a world backup file; which would mean a server restart, etc. Making it not exactly viable plus Geo isn't online all the time, to restore it from a backup once per day, and to add insult to injury; this would prevent us being able to get anything built on New Haven and have them kept until the StarryPy3k devs sort this issue out anyway. Thus this block was implemented.
Once StarryPy3k updates to include protection when it comes to terraformers, and thus prevent this issue. Then we'll be able to get rid of the ban and remove the block.