When I generate a world with your mod the transition from the underground to cavern layer either has a gap of the sky in it, or is just 1 sharp line.
The transition from the cavern to near-hell also always has a gap.
I'm on the stable version of TModLoader 1.4
(If u want screenshots/more info just reply asking for some, or ping me on the TModLoader discord (I'm Shadowspawn))