Fermata on multi measure rest

[Antti Kaihola]

Is there a neat way to have a fermata centered on a multi measure rest?
I'm using:

{
  \once \override Script #'extra-offset = #'(2.5 . 0) s1*0\fermata R1 |
  \repeat unfold 5 { c4 d e f | }  % some music to fill up the staff
}

Unfortunately I have to adjust the extra-offset whenever my layout
changes.