Libertinus: Number height

[fontu]

The number "1" looks lower than "2" below. Can they look the same in height?

[hvoss49]

The difference is less than 0.01mm, which cannot really be seen:

\documentclass[12pt]{article}
\usepackage{libertinus-otf}
\newsavebox\NBox
\begin{document}

12 \sbox\NBox1 \the\ht\NBox
%
\sbox\NBox2 \the\ht\NBox \llap{\rule[\ht\NBox]{3cm}{0.1pt}}

\end{document}

[georgd]

While the measured difference is minimal, the optical appearance is what counts here. And due to the acute top of the1 it looks shorter than the other numerals with bowed or broad top. Hence, the lining numeral 1 (and 4 and potentially 6) usually need most overshoot at the top. That’s clearly missing here.