Mirko Sabljic wrote nice few lines of JSFL which are enabling Allow Smooth on all bitmaps in library
you can find download at http://www.hagane-studio.com/download/jsfl/AllowSmoothing.jsfl
you can set compressionType in jsfl script to produce results you want
I think Mirko did great job !
for more informatio about how to use this script go to my blog post