polytable package incompatible

[mbertucci47]

The environments of the polytable package are incompatible with the table tagging code. The example

\DocumentMetadata
  {
    lang=en-US,
    pdfversion=2.0,
    pdfstandard=ua-2,
    testphase={phase-III,math,title,table,firstaid}
  }
\documentclass{article}
\usepackage{polytable}

\title{polytable tagging test}

\begin{document}

\begin{ptboxed}
\defaultcolumn{l|}\column{.}{|l|}
\> left
\=3 first of three \> second of three \> third of three
\=r right \\
\defaultcolumn{r|}\> left \=2 middle 1/2 \> middle 2/2 \=r right \\
\> left \=3 middle 1/3 \> middle 2/3 \> middle 3/3 \=r right \\
\> left
\=2 first of two middle columns \> second of two middle columns
\=r right \\
\end{ptboxed}

\end{document}

errors with

! LaTeX Error: Control sequence \g__tag_struct_5_prop already defined.