Felix Griffin's Editor Mod
Original Portal 2 style, haven't tested other styles but can do so if you want.
Doesn't work on the top side. I had 2 drawbridges in a horizontal position and across from each other, forming a 3 square wide surface. Bounce gel had no effect across the entire 3 square surface (so not only the square where both bridges touch).
Also, there seems to be a weird lighting issue with the draw bridges as well. When placing draw bridges with a portallable surface across from each other, one looks a lot darker than the other. The presence and placement of one or more light sources such as light strips or obs chambers have absolutely no effect on this. The lighting issue seems persistent in it's orientation, i.e. it always happens on the same side of a chamber. When placing the draw bridges in a similar setup but turned 90?, the lighting issue will thus happen on the same side of the room, affecting different draw bridges than before.
This is also in Original Portal 2 style.
To illustrate both issues:
Bouncing gel
None of the bouncing gel placed across these draw bridges works, simply doesn't bounce.
Lighting
As you can see the top 2 draw bridges are much darker than the bottom two.
When turning the draw bridge setup 90? the lighting issue does not turn. It is clear that it relates to orientation and not to placement of any item or light source, as you can see here:
If you need any more screenshots or want it tested in other styles let me know.
As always thanks a lot for your time and effort!