A document has a mix of SVG and PNG images. Changing the parameters for
`\setupexternalfigure` affects both SVG and PNG images. Consider the
following code:

    \setupexternalfigures[
      order={svg,pdf,png,jpg},
      location={local,default,global},
      directory={images},
      maxwidth=\textwidth,
      maxheight=0.4\textheight
    ]

I'd like to change the `maxheight` option for only PNG images, such as:

    \setupexternalfigure[
      method=png,
      maxwidth=\textwidth,
      maxheight=\textheight,
    ]

However, this affects SVG images as well.

How do you apply different external figure setups based on image type?

Thank you!