horizontal lengths in smaller staves

[Werner LEMBERG]

I use

  \override Tie #'minimum-length = #3.5

This works fine in normal-sized staves.  But in staves created with

  \new Staff \with {
    fontSize = #-4
    \override StaffSymbol #'staff-space = #(magstep -4)
  }

the 3.5 units are relative to the normal-sized staves, which is too
big.  Ideally, I would like to write

  \override Tie #'minimum-length = #(* 3.5 staff-size-factor)

or something similar.  Is this possible?  If yes, how?


    Werner