Success! Looks like we've fixed this one. According to our records the fix was applied for
Needless dependencies: Component->util.Floating->window.Window->half the framework
I'm trying to create a minimal build that will let me use the component lifecycle to manage some custom frontend widgets and I've run into a false dependency in 4.2.1 that brings in half the framework:
Ext.util.Floating depends needlessly on Ext.window.Window, which in-turn depends on Panel and subsequently tons and tons of things I don't need for just piling some HTML and behaviors together in a <div>
The only dependency I found within util.Floating's source relating to windows was Ext.WindowManager, which could be required directly and has no further dependencies.
Thanks for the report! I have opened a bug in our bug tracker.