Hi, as you may know the Create mod has a feature where their trains can be linked through nether portals, and it also works with Aether portals and I think possibly some other mods too. I don't know how difficult it is but it would be cool if this feature worked with this mod's portals too, as it seems like looking through your code you just extend minecraft's portal block. I'm not that experienced with modding to know how difficult this would be to do but it would be really cool if I could add a train to my train station to be able to take me straight to the undergarden!

will be a thing in 0.9.2 once released