This is all just spitting in the wind, so BACK UP EVERYTHING before you do this. Got family? Back them up too! Not becuase this will break them; it's just a nice thing to do.

Ok, I love this mod, but want more and instead of bothering Sam with yet another 'hey, i want you to do this mod this way because I'm too lazy to do it mesself' message, so here's how I did it.

(back up everything. Last warning)
Navigate to: C:\System\Program Files\Steam\steamapps\workshop\content\294100\725747149\(VERSION NUMBER)\Defs\TerrainDefs (The C drive is default to most PCs, if you have Steam installed on another drive, it will be that letter instead.)
Because of how things update, in the folder "725747149", you will need to load the current version number (EG 1.2).

Open file: "Terrain_TS.xml" in Notepad.exe
Search for: <terrainAffordanceNeeded>SmoothableStone</terrainAffordanceNeeded>
Change that line to say: <terrainAffordanceNeeded>Heavy</terrainAffordanceNeeded>

You may get a red-line error when starting RimWorld next, but now you can build soil on both rough and smooth stone.
You can also build it on anything you can put a wall on...
If you want to change this, you can always replace it with 'Diggable' rather than 'Heavy'

I don't condone the re-distribution of other's work, but a little editing (modding a mod) for personal taste seems like a compromise.

ALL CREDIT GOES TO SAM FOR MAKING & CODING TILLED SOIL (I just spent an hour looking how to make it do stuff I wanted it to and figured i'd share it since NO other mod does what I wanted it to do haha)