Hi! IMHO, taskbars of multidesktop taskbar should only resize when they are getting overpopulated. It would make the panel more predictable.
Keep taskbars the same size by default, when a taskbar is running out of free space it should get space from others which still have.
Right now there are too many resizing events happen: when dragging buttons between taskbars, when traveling between desktops with sticky windows, opening/closing windows. It is too dynamic, jumping back and forth