For some reason the sharpness/richer colour is more noticeable in its chrome version.
That stated IT HAS NO CONTROLS, none are shown in the preview panels. The detail sharpened is as it at very small 1x1 or 2x2 level.
Since at the moment of this post there are no free add-ons that sharpen VIDs this is best.
My hope is that a 2x tick box is added.

No control bar appears when switching-on extension, like it is shown in description...
Thus, no ability even make a try any of the effects... :(