I am glad to see that Jérôme is still available. I did compile an OS X binary for Hatari 1.6. It is at atari-forum. However, Jérôme's Xcode configuration and setup is much better since it creates a Universal Binary. I do not have the time to learn how to change the Mac preferences to add the new sound preference. So far, I have contented myself with using the SDL preference screen if I wanted to change something that was not in the Mac preference screen. Also, Jérôme's configuration has the Mac alert boxes working correctly.
I tried set the ALERT_HOOKS variable, but it did not work for me.
As far as SDL is concerned, they have a pre-release version of 1.2.15 at: http://www.libsdl.org/tmp/prerelease/SDL/. This fixes the full screen bug in 1.2.14 that Jérôme patched in the version he included in Hatari 1.5.0.