You also said previously, "Note that, you don't need to do this, if you install the Hawaiian Airports (even in Trial), because their installer already contains all the needed updates." So which one is it.
That's still stands. If you install the Hawaiian Aiports after having installed all the sceneries, it takes place of the Stand-Alone Addon Manager.
However, you said "I unistalled all sceneries again. I then installed the Honolulu scenery.". To this, I just replied this is to be expected, since you havent's said if you have installed either the Stand-Alone Addon Manager AFTER PHNL OR the Hawaiian Airports AFTER PHNL.
I don't want to go through all the work of loading all of the sceneries if I can't get the latest one to work.
You said you uninstalled all the sceneries so, it's obvious that, if you uninstall them all, you have to reinstall them all...otherwise how do you expect they'll ever show up, if you uninstalled all of them ?
Nobody told you had to uninstall all the sceneries, I've only said you have to install the Addon Manager Stand-Alone (or the Hawaii Airports, it's the same) AFTER all the sceneries are installed. This because, if a scenery is not installed, it can't be updated of course.
If, instead, with "all the work of loading all of the sceneries", you mean *downloading* all the sceneries, then no, you don't have to download them all again, you only need to install the Addon Manager Stand-Alone (or the Hawaii Airports, it's the same) AFTER all the sceneries are installed.