Hi, insert a FloatingTile as Keyboard, I can change the size of the black keys but I can't change the height of the white keys as it only changes the size of the object.

You can change pretty much every aspect of the keyboard.
But you don't change the size of the black keys, only their relation to the white ones.
I think what you're looking for is called "DefaultAppearance" if you set that to false you can change
the size, cropping and aspect ratio.