Ugh... another wrench in the works. On Catalina and Big Sur, if you hide an app's dock icon while it still has windows open, those windows disappear entirely. You can only bring them back by programmatically ordering them back in. Luckily that is an uncommon case - you'd have to have a visible window that transitions to one that wouldn't have a taskbar icon (e.g. by gaining WS_EX_TOOLWINDOW or losing WS_EX_APPWINDOW). I suppose the patch could either just not support that transition, or gate it to only happen on OS versions where it works.