Well, I have Cantabile, and another similar program called Forte, from Brainspawn. I also have been a Sonar user since the dinosaur days.
I use Cantabile/Forte for live performance situations, where I can stack layers of VST synths into really easy to call up presets, and either program REALLY fits the bill for live performance.
IF you are talking about continuing to use Cantabile or some other VST host wrapper rack emulator for LIVE performance, then I would vote for that, rather than for trying to get Sonar to serve up presets in any kind of timely manner for live performing.
Sonar EXCELS at being recording software. Cantabile/Forte EXCEL at being live performance VST hosting software.
In my opinion, Sonar has way too much overhead to effectively act as a VST host for live performance - it takes too much time to switch presets using Sonar, as it is just not built to do the kinds of things programs like Cantabile or Forte do in support of live performance.
So, perhaps you can elaborate on what you DO do, using Cantabile, and what you want Sonar to be able to do?
I'll try to help, as I have over 10 years of live performance using both Forte and Cantabile, and somewhere around 30 years of Cakewalk software use.
Bob Bone