Only needed the blue gel.. No neeed for the cube, or funnel.

Perhaps making the button/cube also needed to open the door. This would force me to do the puzzle the correct way.

On second go, avoiding the exploit, I didn't need the reverse funnel. Just a touch blue gel in exit room. Once I got the funnel, I just bounced with cube and threw it into the funnel near the button.

The timing is really hard. plus i fell off the elevator at the end. Maybe you can make the funnel longer?