Your solution is no longer possible. Thank you for your response :)

Exactly. What temporarymanwastaken said is spot on.
I exploit this concept in my Hobby #3 puzzle.

Probably by standing in the portal over the water/goo and moving the other portal to the top of the stairs. Takes a bit of practice to do without getting shoved out of the portal and into the goo when the exit moves. Probably best just to stick grating on it, so it's still visible from the room but can't be used for anything other than the funnel.

So enlighten me how did you do that and I will correct that.

That was really quite fun!
However, I was able to solve it without using the weighted button located right next to the main entrance.

Updated !

The ball still rolls off the button at the end. Maybe the button could trigger a funnel to hold it in place?

Updated

Thank you for your comment. In fact you don't have to carry the cube with you. When you are at the exit point you can get the cube from that place, but thats up to tester.I will think about this 'tunnel crossing' as well. But it seems okay that there are 2 possible ways. When it comes to the second part of your comment, yes, I will improve the second ball puzzle probably by adding more 'walls' so the solution should be more enjoyable and somehow easier. That needs testing. I will write a comment when updated. Thanks.

So I tried taking the companion cube with me and it got fizzled. And then I carried the laser cube to the end? Not what I expected. I think the white panel placement threw me off. The intended solution looks like the funnel, to cross the water and climb the stairs, but I portaled across the water instead, and brought the cube along. The second ball puzzle is a good idea, but it could use some improvement. It's too hard to steer and too easy to crush and fizzle.