% A node taller than its band by more than 4mm must dirty the build.
\documentclass[border=2pt]{standalone}
\usepackage[en]{superfig}
\sfsetrole{x}{sfTeal}
\begin{document}\begin{tikzpicture}
\sfrow{R1}{8mm}
  \sfnode[role=x]{A}{tall}{16mm}{16mm}
\sfrowend
\end{tikzpicture}\end{document}