With the current default behavior of the Splitter, when a user manually drags a Splitter pane to resize it, the component stores the pane's size as an absolute pixel value (i.e., flex-basis is set to a pixel value), and this is by design.

This means the pane does not scale with the browser window, unlike panes that have not been manually resized.

It would be useful if the Splitter could convert the pixel values to percentages on window resize, so that all panes continue to scale proportionally regardless of whether they were manually resized.