I frequently switch between a single screen (laptop) and a dual-screen setup. On the secondary screen I can add another panels, which works just fine and is very useful (e.g. I can have two window button plugins displaying windows from the current screen only) but I have to destroy that nicely configured panel when I switch back to a single screen configuration. It would be good if the panel could memorize which screen it was configured for, and to hide itself[1] if that screen isn't available. (yes, I'm aware of "span monitors" option, but (1) it only works if the panel orientation matches the screen layout (e.g. both horizontal), (2) it treats both screens as a common workspace, which isn't what I want to achieve). [1] I wish there was also an option to manually disable the panel without destroying it, but that's separate from this bug report.
This is possible with the "primary" option now.