Hello David,
as you can see in the following snippet, there are several ways to
print text above an empty measure; all of them wan be moved using the
appropriate object name; besides since all of them accept the \markup
command, all of them accept \translate as well.
The third one is what I would recommend to print the tempo indication
(you don't have to put it after the rest, because it's aligned with
the barline or the clef).
Regards,
Valentin
{
\override TextScript #'extra-offset = #'( 2 . 0 )
r1^\markup {"normal" \translate #(cons 2 -3)"rest" }
\override MultiMeasureRestText #'extra-offset = #'( 2 . 0 )
R1^\markup {"multi-measure" \translate #(cons 2 -3)"rest" }
\override Score.RehearsalMark #'extra-offset = #'( 2 . 0 )
\mark \markup {"as"\translate #(cons 2 -3)" a mark" }R1
}