DVD is a locked format, nothing will ever be updated or changed.
DVDSP is by far the best full featured authoring app on the Mac. It only comes in Final Cut Studio, you can still get version 3/2009 from Apple. All the software is EOL as far as development is concerned.
The other full featured authoring program is Encore, which comes with Premiere Pro. Some people love it some people don’t but you can author with it. It also does entry level BluRay authoring.
They pretty much it for authoring on a Mac.
BTW – all menus should be created outside of the authoring app it you want professional results.