Something similar to textLengthOn

[Leo Correia de Verdier]

Dear list!

Does a command or function exist that would force the horizontal spacing to 
adapt to a markup, something like textLengthOn, but that would only take the 
current context into account? If not, would it make sense to try to create one? 
(Asking just due to my lack of understanding of the inner workings of spacing).

Thanks a lot!

/Leo

%%%%%
\version "2.20.0"
\new Staff <<
  \new Voice { 
    \textLengthOn
  f''2 ^\markup "I would like these markups to force "
  \textLengthOff
  f''2 ^\markup "the spacing only when a new note "
  f''2 ^\markup "appears in the same voice/context" 
  }
  \new Voice { 
    \repeat unfold 8 c'8 \noBreak c'2 
  } >>
%%%%%%