Switching between already open windows is usually a function from the operating system. On my Linux box for example, I can press [Alt + Tab] to rotate through open windows, and then either hit [Tab] multiple times to rotate through them, or click one with my mouse’s left button.
I also have multiple “work spaces”. Each is a complete desktop, and can it’s own set of open program windows. It’s a quite nifty feature,but I use it rarely myself on my multi monitor setup.
Getting to the DRC window from it’s default location in the menu:
PcbNew / Inspect / Design Rules Checker or: “[Alt + i] + d” seems easier to me than duplicating this in yet another menu. I find duplication of functions in different menu’s often more annoying then useful. Especially if you do not know where a specific (seldom used) function is and you start searching through the menu’s.
Also: In the button bar in Pcbnew, there already is a button to directly open the schematic (even if it is not opened yet)
and similar for Eeschema, to directly open Pcbnew.
I’ve heard some rumors that KiCad V6 may get configurable toolbars, so you could add a button for switching directly to KiCad’s project manager.
Yet another nice thing that my Linux desktop does for me is grouping windows in the taskbar. For example, My main menu is on a 1920x1200 pixels monitor in portrait mode.
This is a screenshot of the top left corner:
The dark and light grey rectangles are representations of 2 complete desktops, then there is a menu with 3 KiCad programs. When I open it, it lists the current open KiCad windows (With tooltips)