Hey @eplees thank you so much for posting about this and for working on data biographies. I am not aware of any ACS data biographies other than the King County one:
https://www.communitiescount.org/data-biographies
but I do know that lots of people are working them! If you want to get a little more insight into the specifics of the King County process they joined us for a recent Talking Data Equity and the video is here:
I do not know about the effect of undercounts in the Decennial Census and weighting nor the impact of entropy weighting on that. However, now that you’ve raised it, I’m very interested and will look into it. I’m going to see if we can find an expert on that to join us at Talking Data Equity.
If you have any new insights since posting this, please definitely add an update here and tag me! 
Sorry about my slow reply - I’m just catching up 