If anyone wants to take a stab at fixing it, I've included a replay of the intended solution.
Intended solution is quite cool
I think you gave too many constructive skills and they are being abused for backroutes.
So, here's my opinion on how to block such backroutes
1) -1 platformer and +1 cloner for compensate. Move steels to the right.
This way, the glider is stuck in infinite loop so the floater don't have to platform over the exit. He can just fall and climb to the right.
Left picture is fixed version from me and right picture is original version
After the floater climb to the right, you can clone the glider and bash the one way arrow wall.
2) -1 builder and +1 cloner for compensate.
On your solution, two builders on the right side of the map can be replaced by one builder+cloner
So in conclusion..
-1 platformer
-1 builder
+2 cloner
+2 save requirement
move steels to the right a bit
I attached level file and my solution replay for it.
Hope this will at least help you improve your level.