Using scale in the enclosing tikzpictures gives wrong coordinates outside "axis"

[Rmano]

This could be related to #375, and probably the answer is "don't do that" (*), but:

\documentclass[border=10pt]{standalone}
\usepackage[T1]{fontenc}
\usepackage{pgfplots}\pgfplotsset{compat=1.18}
\begin{document}
\begin{tikzpicture}[
    scale=0.8 % transform shape doesn't change anything
    ]
        \begin{axis}[grid=both, no marks]
            \addplot {x};
            \path (0,1) coordinate(splat) node[circle,draw]{};
        \end{axis}
        \node[draw=red, thick] at (splat) {};
\end{tikzpicture}
\end{document}

If you comment out the scale, you have the correct:

I have a much more complex example, if you want, with a circuit and a couple of axis that show waveforms. I tried to scale the whole diagram to fit with scale=... ; transform shape and found this problem.

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(*) You can avoid it, obviously, but sometimes it is not handy... Using an external \scalebox makes alignment of the whole picture with baseline=(some internal node) quite horrible, and the result is not the same (line thickness, for example).