Let temporary minibuffer messages replace current minibuffer contents?

Hi,

as I like to restrict the minibuffer to one line max height
the current mechanism of adding temporary messages at EOB
is not working well in some cases. E.g. when the "Find file:"
shows already a longer path and then you press some wrong
key, the "Command attempted to use minibuffer while in minibuffer"
is almost invisible as it wraps to the next line (that I forced
to be hidden).

xemacs is showing such temporary message instead of the current
minibuffer, i.e., completely replacing it for the given timeout.
then restoring the previous content.

I wonder if it is possible to reach the same for emacs. After
looking through minibuffer.el I couldn't find a way. Redefining
minibuffer--message-overlay-pos to return 0 didn't help as the
prompt will stay at the EOB.

I could just think of advising minibuffer-message to save
and clear the minibuffer and restore it after the timeout,
but I wonder if there an easier way to reach that?

cu,
Frank