in a heavy scene file I was running into issues dealing with the geo and blendShapes and just wanted to kick out some things without having to deal with the ui. ( I had also transferred UV maps which kills basically everything until you get rid of history )
so for exporting the blendShape maps the command is part of the ART brush commands and will open up the file dialog for size and where you want to save the exported image file
// export maps
I also wanted to smooth flood the hell out of my painted maps, but I didn't want to sit there hitting the "flood" button forever.. so I just wrote an uber simple loop script.. What's weird to me is that the flag that coincides with "flood" .. is -clear.
int $i = 0;
while ($i <= 25)
artAttrCtx -e -clear `currentCtx`;
also this is all in Maya 2016. so I am not even sure what works and doesn't in 2017 yet with blendshapes, and blendShape wt maps.