What I am trying to do is to fill the whole usable screen on a netbook.
So I set .Xdefaults XEmacs*EmacsFrame.geometry to something larger than
screen size. Xemacs starts, filling the whole screen, then as
.xemacs/custom.el is evaluated it redisplays toolbar in a different
place. Next the window is made smaller by the space the toolbar did
originally ocupy and still much smaller than the specified .Xdefaults
property.
On a netbook the wasted screen space is quite noticeable and the same
happens when toolbar is disabled completely.

This behaviour defeats even the maximus window manager utility that is
supposed to maximise windows by defaults on netbooks.

Are there better ways to set window size than .Xdefaults?