Here is my entry. I used hammer and a concept that I came up with some days ago:
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=908715737

Best:
1. Evolution by SloppySteve
2. Just Test: Decayed by nintendo.erk
3. majiqB by Byzarru

Most Improvment:
1. Evolution by SloppySteve
2. Just Test: Decayed by nintendo.erk
3. majiqB by Byzarru

Worst Original:
1. Pumpnjump by SloppySteve
2. Just Test by nintendo.erk
3. Magic Box by Byzarru

After I've been told that you can actually not only change your layouu but the puzzle itself, I made a new version. I've overwritten the old test so you basically can open Portal 2 and it will automatically download the new version.

Here is my entry: https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=895173344
which is a rebirth of: https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=74856236

1. Fluctuation by Gigopler
2. Loopong by Polux
3. Furrows by Almisuifre