SVG images are not sized properly (--mathsvg + dvisvgm)

[xworld21]

trafficstars

Creating math images produces poor sizing and alignment, for instance

\documentclass{amsart}
\begin{document}
  Alignment test: $\underbrace{x + \dots + x}_{n\text{ times}}$.
\end{document}

through latexmlc --mathimages produces My guess is that the scaling passed to dvisvgm does not match the scaling applied to the depth, hence the poor vertical alignment.