It would be great if expand can be set to a negative value for hlinex and vlinex to shorten the line. As of now, setting expand to a negative value does not seem to do anything (v0.0.6).

#tablex(
  columns: (100%,),
  auto-lines: false,
  hlinex(expand: 1em),
  [],
  hlinex(),
  [],
  hlinex(expand: -1em),
)