The dim-line break test used text_half + DIMGAP as its vertical
threshold, but DIMTAD 1/4 places the text exactly text_half + DIMGAP off
the line. The two terms cancel at the same DIMSCALE-scaled value, leaving
the comparison on the knife's edge — so a gap flickered into the line
depending on the DIMGAP/DIMSCALE combination. Drop DIMGAP from the
vertical threshold so above/below text stays strictly clear and the line
stays whole; centred text (DIMTAD 0) still breaks for the DIMTFILL
background. The horizontal half-width keeps DIMGAP so a real break clears
the text. (#94)
Co-Authored-By: Claude Opus 4.8 <[email protected]>