Full window video rather than full screen

Dear Brave,
I would like to suggest a new way to watch videos, which I never found in any other navigator: Having a way to see a video in “full window” rather than “full screen”.
The target is more or less the same as for the full screen: getting rid of various surrondings that are not necessary to watch comfortably the video. But being able to do something else on the screen at the same time would be great. Also, we would be able to adjust the window size, that can be better adapted to the low definition or whatever size is more neat for the user.
This possibility would also be very useful in association with an “always on top” that used to exist in the past in firefox, that allows to work in a window without losing the view of the one on top, what is far more efficient than adjusting windows sizes permanently.
Thanks for your understanding.