Doesn't work with borders.
Picom tends to apply the shadow incorrectly.
If anyone wants to contribute to this, feel free. I am not planning on making this work better in the forseeable future as it's really not that popular.
I have had this crash my WM on boot once in a blue moon. This happens rarely and should NOT happen when the WM is already running.
If anyone has a solution, feel free to contribute.
If you want to be 100% safe, use bar_enabled=0 in the config.