\paper { tagline = ##f }

orderYouSeeThis = 
{
  \override TextSpanner.bound-details.left.text = "1st I see this,"
  \override TextSpanner.bound-details.right-broken.X = 94.5 % relative position, staff start is its origin
  \override TextSpanner.bound-details.right-broken.text = "2nd then this,"
  \override TextSpanner.bound-details.left-broken.text = "3rd now this:"
  \override TextSpanner.bound-details.right.text = "4th I understand this!" 
}

ritTextSpanWithBroken = 
{
  \override TextSpanner.font-shape = #'upright
  \override TextSpanner.font-series = #'bold
  \override TextSpanner.bound-details.left.text = "poco rit."
  \override TextSpanner.bound-details.right-broken.text = " " % without value, defaults right.text value
  \override TextSpanner.bound-details.left-broken.text = "(poco rit.)"
  \override TextSpanner.bound-details.right.text = "a tempo"
}

\relative c'' {
  \orderYouSeeThis
  e\startTextSpan e e e |\break
  e e e e\stopTextSpan |\break
  \bar"|."
  \revert TextSpanner.bound-details.right-broken.X
  
  \ritTextSpanWithBroken
  e\startTextSpan e e e |\break
  e e e e |
  e\stopTextSpan e e e |\break
  \bar"|."
}