Different height and width in windowed?
Using percentage if possible, like x% of the current window.
And a feature that if window size is <= x% of max_height and max_width (take 150% for example) it would disable thumbnailing on seekbar. (This feature would be good for people like me who uses pip a lot and don't want thumbnails to take up the entire small window when seeking)
This is better implemented as hot-reloading of script-opts, which the user can configure to change with any condition through an auto-profile.
The script isn't currently written with that in mind so it'll take a bit of work.
honestly the ideal way to do it would be to do away with max_width and max_height and just scale with the width and height, something like mp.get_property_number("width") * scaleopt where scaleopt would by default be 0.1 for 10% of the vide's size.
That way thumbfast's size would remain consistent in relation to the window size.
Might not be too hard to set up in auto profiles.