SUMMARY Entering and exiting fullscreen on Mac systems is a heavy, laggy operation. My previous bug report addressed a flaw in the implementation of the current design, but I believe the design itself is flawed. Toggling fullscreen mode and toggling the palettes are separate concerns, and I believe they should be treated as such in this case. The use case of hiding all palettes while keeping the window as a window is a real thing. Currently the only way to arrive at such a combination of modes (fullscreen off, canvas-only on) is to enter canvas-only, and then exit fullscreen, which is just exploiting a glitch in the implementation. I propose totally decoupling the two modes. Simple, independent toggles for each. No automatic magic.
Yes, this is an issue with macOSX. Please report to Apple. Given that you do not provide a link to your "previous bug report", I might lack a bit of context, but... The change between full-screen and none-full-screen is not something that's done inside Krita, it's Apple designed. So please take that upi with Apple. You can hide all dockers with a simple shortcut while not hiding the rest of the affordances in Krita anyway, and that's been avaiable since 2006. Assign a shortcut to "show dockers" in Krita's settings. There is no default shortcut, because people who don't understand how computers work would accidentally hit the default shortcut would hit that and then file a useless bug report because they would have lost their panels without knowing what they were doing. And you can, of course, define which parts of Krita are shown and hidden in canvas-only mode in the settings, and that includes the dockers.