One other bit of news on this topic.
There is a
discussion thread in Amazon's Kindle help forum where customers are expressing their unhappiness with the new widow/orphan behavior in the 5.12.2 firmware. One of the posters claims they were told by customer service that the "kindle team is working to resolve this issue through a new update, which should kick in in about a week".
I have my doubts. I believe that Amazon is going to fix the firmware, but are they going to revert to the prior behavior or just keep the new default and obey w/o overrides if present in content? Also, a fix in a week seems unlikely since Kindle firmware comes out approximately quarterly and 5.12.2 just came out about a month ago.