Ledger lines drawn over glyphs that are too close

[henryso]

MWE:

\documentclass[12pt,letterpaper]{memoir}
\usepackage{gregoriotex}
\usepackage{fontspec}
\usepackage{libertine}
\grechangedim{punctuminclinatumunisonshift}{0.02500 cm plus 0.00182 cm minus 0.00546 cm}{scalable}
\gresetlinecolor{gregoriocolor}
\begin{document}
\gabcsnippet{(c4) Test(LL)}
\end{document}

Produces:

I don't think this is too far-fetched. I was using the punctum inclinatum to represent notes of a trigon that happened to be above the staff.

[olivierberten]

I guess these are related: Lau(b!ce~)dá(f')mus(c) te.(b!ce.) (::)

sú(il!mv)sci(l)pe(l')

[henryso]

My TeX is not strong enough to come up with suggested code to generate. Can anyone suggest something?