So far, I've created dialogs in UIL files as unmanaged widgets
controlled by the main window.

This means that when do the MrmFetchWidget of the main window, all
widgets are instantiated, parsed, processed etc. And widget parenthood
is hardcoded in the UIL.

is there a way to code totally independant widgets in a UIL file that
can later be instantiated when/id needed and then managed as a child of
another widget ?

(think of a dialogue for instance which could be popped as a child of
another dialogue or as a child of the main window).

I am thinking that by having a whole bunch of seldom used widgets
separte from the main window, the application startup will be quicker
since MrmFetchWidget won't have to instantiate a whole bunch of widgets
whihc may or may not be neeed during execution.