Thanks,

Your reply popped up here exactly the moment I saw the light! Must be something 
Messed up the order things:

Was:
\scale[\scalesetting]{%
    \expanded{\useMPgraphic{\xmlatt{#1}{name}}{\xmlatt{#1}{parameters}}}}%

And of course had to be:
\expanded{\scale[\scalesetting]{%
    \useMPgraphic{\xmlatt{#1}{name}}{\xmlatt{#1}{parameters}}}}%

On 25 Apr 2016, at 13:22, Hans Hagen <pragma@wxs.nl> wrote:

On 4/25/2016 1:11 PM, Meer, Hans van der wrote:
With images one can scale them on placement, for example \externalfigure[][scale=250,height=..] etc.
Is such a scaling or separate height,width setting also possible with the placement of useMPgraphic?
Or needs all scaling of thesebe done within the metapost/metafun code?

\scale[...]{}


Hans van der Meer