Hint, why in the Doom Builder 2 thread, I said that there's about a dozen plus ways for this to fail.

You can do it, but it's extremely time consuming to fit all the restraints of the portal effects.

and now I can finish coldman's stage (way too awquard to make the tower platforms as solid blocks)

I don't actually reccomend doing this. I made this to show you how it's possible but really comes with really bad side effects.

like the mirror effects on invisable walls, I'm trying to see if I can remedy that though