Some work has also been done on this already:
https://github.com/autopkg/recipes/pull/61
It's unfortunate that Adobe would change their pattern so late in the
lifecycle of Reader 11 - assuming we do merge in a separate set of
"Updates-only" recipes from Matthias's proposal, it will make
deploying Reader more complex, where there is some base version of
Reader and then updates on top of it, at which point you may want to
stop importing the base versions in case they get later updated again,
etc.
Tim