Clash between textpos and pmboxdraw

I’d like to include icons from the package pmboxdraw into a beamer slide.

However, this package defines a square icon textpos which is re-defined by textpos.
I can’t use another square because I’m using it to have an increasing gradation like this : ▁ ▄ ▆.

What can I do to avoid this package clash ?

Here is a problematic MWE :

documentclass{beamer}
usepackage{textpos}
usepackage{pmboxdraw}
begin{document}
    begin{frame}
        pmboxdrawuni{2582}
        pmboxdrawuni{2585}
        textblock
    end{frame}
end{document}

The thrown error is : Command textblock already defined. pmbd@UniDeftextblock{2588}.

documentclass{beamer}

usepackage{pmboxdraw}
lettextblockpmtextblock
lettextblockrelax

usepackage{textpos}

begin{document}

    begin{frame}
        pmboxdrawuni{2582}
        pmboxdrawuni{2585}
        textblockpm
    end{frame}

end{document}