When using a laptop and switching from using the laptop's screen and an external screen with higher resolution, it is oftentimes the case that the ideal size for the panel with the taskbar is very different in both – a normal-to-large sized panel in a high-resolution screen shifts to a very small and almost unreadable panel when using the laptop's screen (which oftentimes have smaller resolutions), and one has to re-adjust its size to use it comfortably and later re-adjust it back when using the screen again. Would be nice if the panel could scale its size more smartly with resolution changes, just like window's or mac's panels – or if not possible, to remember sizes for different resolutions.
*** Bug 393661 has been marked as a duplicate of this bug. ***
>or if not possible, to remember sizes for different resolutions. It does remember width. We used to remember thickness per screen, but that got a lot of bugs as it made the behaviour appear random. Ultimately given you're doing this for high DPI this is completely the wrong approach. Use of wayland scaling will make things consistent physical sizes.