Created attachment 2462 the example I'm using 64px sized vertical panel and primarily psi im-client. While encrising numbers of icons in the row (1 to 3 on example) everything works OK. But when I want to decrease number of icons in the row (3 to 1 on attached example) scaling works incorrectly. The panel restart doesn't helps, but after restart of application the panel restores normal display.
This is because a lot of plugins do not respect scaling of tray icons, not much we can do about it.