Currently, when you modify the palette to have a scrollbar, hovering over it and scrolling moves the viewport for the diagram and does not scroll the palette. As far as I understood html / css, a scrollable div should generally react to scrolling when hovering, so my question is how was this disabled here and what would I have to do to re-enable it.
To reproduce, simply add the following css to an example project, i used properties panel extension.
.djs-palette {
height: 150px;
overflow: scroll;
}