Adrian, unfortunately, you are correct, and Dion has not looked at this issue thoroughly, so Dion is incorrect in this regard.
Unfortunately, there still
is this huge flaw in Marvin 3 Beta right now in that in the
comprehensive authors listing, it's impossible to sort authors by their last names, no matter which setting you select. The settings only affect
partial Library listings, but not the "all authors" listing where, of course, it's needed the most!
Like Adrian says, I would find it unacceptable for Marvin 3 to be released
without enabling this essential and "smart" (if you will) authors listing. If you ask me, ladies and gents, I find sorting writers by their first names
only to be... crude (to put it diplomatically).

Marvin 2 could sort authors by their last names
everywhere (optionally, of course), so, naturally, Marvin 3 should accomplish the same. Generally speaking, each and every Marvin 2 feature should be available in Marvin 3 (but right now it's not).
Also, Kris asked us not to discuss Beta matters in here, if possible. We have a Beta-testers-only mailing list at Google Groups, and I urge any and all current Marvin 3 Beta-testers to subscribe there, and we can discuss any still outstanding Beta-related issues there rather than in here. Just send an empty email message to
marvinapp+subscribe@googlegroups.com to subscribe to the Beta discussion group.
Note: Kris has indicated he would, in all likelihood, not be able to keep up with the discussions in that Google group (and I'm not surprised, given his workload), so the Google Beta group would mostly just be for Beta-testers to discuss Beta-related issues among themselves, to inspire one another, help one another with troubleshooting specific issues, making bug reports/feature requests more precise, etc. For talking to Kris, however, the dedicated email address he provided should be used instead, not the Google Beta group. I keep finding new issues in Marvin 3 every day – I have submitted 2 reports to Kris earlier today, and another one yesterday, so I believe that there are still things to improve before a public Marvin 3 release.