Sean, I'll be sending you a private message after I post this.
"...I see that, indeed, you are right; overlapping in conjunction with the CC64/68 on/off does insure smooth legato..."
CC64/68 doesn't work without the overlapping notes. Overlapping doesn't just "insure smooth legato," - that's how the programming works. Without it, at least in ARIA, there's no legato.
The World manual's information about legato is an abbreviated version of what's in the GPO manual:
"...Strings, brass, and woodwinds can also be used with the Auto-Legato feature as an alternative to using the sustain pedal. This feature automatically detects note overlaps and applies changes to the attack and decay characteristics of the note transitions. Auto-legato is located in the Control tab on the ARIA Player.
Auto-Legato is the most convenient method to use and can give good results when it is applied to take advantage of its intended design, but has some limitations. Those limitations are related to the way it handles polyphony. Its detection of overlapping notes and automatically stopping the first of the overlapping notes in favor of the second means that it functions in what is commonly known as 'mono mode.'
In contrast, using CC#64 is more flexible and can potentially give superior results but requires more work on the part of the user. It is up to the user to place the CC#64 “switch” data in the MIDI tracks as needed. It is also up to the user to precisely determine note overlaps since the amount of note overlap won’t be automatically determined as with Auto-Legato. This gives the user great flexibility in adjusting the sound of the note transitions but requires considerable attention to detail to get the best results..."
So I'm glad you understand the overlap issue now, but why are you saying:
"...Aside from the fact that CCs 64/68 still do not work within my installations of GWI/Aria..."
"...Hopefully I will soon enjoy similar understanding regarding the World Instruments issue..."
? CC64/68 hasn't been working because you haven't been using it correctly. What other issues do you think you're having with World--?
Please check your PM folder, I'll be sending another message later this morning.