Thanks, @Hovering Heavy. Don't know that I'll try to fix this one.

My first playthrough on the last level I phased the cube through the grate to kill the turrets. I got the glitch pretty quick but was unable to reproduce on video. I found an unintended solution for the other two levels as well.
My playthrough: https://youtu.be/jwiVTqH7m_U

Thanks, @quatrus!

Nice puzzle - good use of portal effects. Thanks for creating

Thanks, @Tyr Anasazi!

Great map, it just keeps on going.

Thanks, @Rooke!

The 1st chamber was fun and easy.
The rest took a while to solve.
Overall: