suggestion

Can you make the option as default that show a thumbnail when the mouse pointer floating on the playing progress bar?
I think it must very help.

It already has that option

I know that has that option, but it is not the default option, that's why people use other players for this function, I did too, I spent the whole night trying to find it and turn it on.

Probably not a good idea to have as default as it has a performance impact.
It may not impact everyone but for those on lower end systems or with slow drives, it will likely be very frustrating (to say the least).