So my issue with this mod is that Terraforming is outright useless.
I have this mod for a year now and i NEVER was able to use this feature the games Sector generator makes it sure that the planets allways have at least ONE planetary effect/modifier that cannot be modified/removed to allow for terraforming. every single time. there is ALLWAYS atleast 1 red i cant do anything about. the terraforming is asking for waaay to much to allow for terraforming.
Also improving resources is never allowed. even if the planets is sitting with a bunch of Poor resources.
I'm not sure what you're having a problem with here - terraforming is somewhat expensive and time consuming, but perfectly possible. Obviously you can't terraform molten worlds or gas giants, but pretty much any barren planet can be terraformed. You just need to normalize the atmosphere, have a stellar array (Stellar Shade for hot worlds, Stellar Mirror for cold ones) built, make sure there's some water available, then terraform away.
But let's go over the specific process with an example. Let's say you've decided to do like I always do in 90% of my runs and colonize Penelope's Star. You start by colonizing Ithaca, which you want to terraform into a Terran world - easily done. Ithaca always starts as Habitable, so all you need to do is build an Atmospherics Processor, Stellar Shade, and then have a colony with either Ismara's Sling (Ismara, obviously, is an excellent choice for this) or a station colony (astropolis, mining station, etc.) with Asteroid Processing. Then you just start the terraforming process and wait awhile. Once you're done you can either tear down the atmospherics processor to avoid the upkeep cost, or first prioritize maxing out relevant resource deposits and adding the Mild modifier.
But let's do a more complicated planet in the same system: Ogygia. I've never seen Ogygia spawn with an atmosphere, so first you'll need an Atmospherics Processor and have it do the project to normalize the planet's atmosphere. Then you'll need a Stellar Mirror to begin the terraforming process. You'll also need water, but if you've still got the Ismara's Sling/Asteroid Processor you used earlier then that's no problem. Terraform away and then bam, done.
As for resource improvements, certain planets have certain caps on resources. First off, you can never improve Ore or Rare Ore resources, only Food, Organics and Volatiles. For Food improvements the world needs to be Habitable and you need a water supply from an Ismara's Sling or Asteroid Processor. For Organics and Volatiles the world needs to be of a certain type, usually Terran, Jungle, Desert etc. and then you can improve the resources up to a certain level depending on the planet.