Re: frame title is not updated often enough

[Richard Stallman]

    However, with Emacs 21, the window title updates only every once in a
    while (e.g., not while I type, but if there is some bigger re-display
    going on).

The frame title is updated only in special situations as an efficiency
measure; the mode line too.  Emacs has special code to recognize it
should update the mode line more often when the column number is
shown, and also to optimize when the column number is unchanged.  We
could do something similar for the frame title, but do you really want
to update the frame title after most Emacs commands?  I am sure it is
slower to update the frame title than the mode line.

What was your reason for putting it in the frame title instead
of the mode line?