brundlefly

Mystic38
I regularly use synths/pianos with Sonar, and never dive into the synth menu to turn off local control.
I setup the midi inputs and outputs to the synth and to prevent the midi loopback to the synth I find it much much simpler to just turn off input echo within the tracks of Sonar.

The reason for disabling Local Control and treating a keyboard synth as a separate controller and sound module is so that the keyboard synth won't always be generating audio when you're using its keyboard as a controller to rehearse/record some other MIDI-driven synth (either hardware or software). If the keyboard synth is always generating audio by local control, there's no way to record a track for some other instrument while hearing a previously recorded MIDI track driving the keyboard's sound module without also hearing that module responding to the live performance.

Some users expressed the option to turn local control off, this is not a perfect option.., so I expressed that the option does exist to leave it on and prevent Sonar echoing the data back..also not a perfect option (but not perfect in a different way), but as its an option i have used successfully for many years for multi-part recording i suggested it.
 
The cases for disabling LC that you describe do  exist, however those cases are based on an assumption by you of the synth and its abilities (or lack thereof) for control and setup, and as it is straightforward to dismiss them all by assuming different capabilities of a synth, and include play/rehearse deficiencies in disabling LC, lets just say that there is no 100% right way here...  and it is for the user/synth combo to figure out what works best for them.