One problem was that the 'Genesis Wave' series of books, despite it being a large event, really haven't been followed up on much at all since. I can't recall a single mention in another book since. This despite the fact that many Federation worlds were completely transformed by the changes.
I would like at least some mention as to what happened to those worlds, or if that whole thing is being written off as happening in an alternate universe (even though it's not).
"A Time to Sow", "A Time to Love" "A Time to Kill" and "A Time for War/A Time for Peace" all mention the Genesis Wave and the "Genesis Sector", including ongoing relief efforts (at least in "Love").