This script is exactly what i was looking for. Thanks ! Now i can click on full screen without delays.
Truely, on the time i was testing, my youtube setting was playing videos like i clicked in expand button and wasnt an interference from the script.
So in another use of the browser that i noted it.
You gave me credit, but imo, this is pretty lame... just adds a resizing option and doesn't have any of the new features I added.
This is the original script, by me.