I’m currently trying out ver 10, and I was happy that ver 9.18 added an option to hide the level meter displayed in the plug-in (instruments) window and hiding the toolbar at the top of the window, but that feature is not available in ver 10?
Once, I ran the “Undock plugin editor” and found that the separate windows that appeared could be folded just like in 9.18. By docking it in the window titled Screen Keyboard again, the meter disappeared. I see! So, can’t hide the Screen Keyboard’s tools of top?
Currently the screen keyboard/effect shell that follows the effects/instruments of the selected track has a fixed layout, as you’ve discovered to hide the toolbar and/or meters you need to ‘undock’ a plugin.