Noel Borthwick [Cakewalk]
The main problem with using UAD plugins alongside VST3 plugins has been fixed in X3B. 
After reading this thread its not clear to me what the remaining issue is. From SONAR's side there have been no changes in how UAD plugins themselves are handled. Also UAD plugins themselves are not VST3 so as such its all being handled very similarly to X2.
 
Regarding the message, that is a warning that is displayed from the plugin itself telling you that if you sandwich non UAD plugins in a UAD plugin chain you will incur latency. The plugin knows this because of SONAR's support for the UAD chaining API. As I said earlier any such message can be suppressed only from the plugin so the fix needs to come from UA. Unless we disable the integration completely which would result in less efficient streaming. 
 
So what is the remaining issue besides this? Latency is expected if you sandwich other plugins between UAD plugins. Thats how their design works and you will see exactly the same behavior in any version of SONAR.

Hi, Noel. The issue I reported was the message popping up about about the  plugin chain and the resulting latency. I quoted your original post in this thread and they responded that they'd fix it soon.

Cool thanks for the update. I think the resulting latency is expected though AFIK. The message they may be able to fix. Can you please ask whoever you spoke to to get in touch with me? I want to make sure that they are not testing for the application name since it will vary across SONAR versions.

Will do.

There are several issues with UAD-2 and X3. I'm having a problem where not all plugins are activated upon opening a saved project though X3 is showing they are powered on. Another issue is when dragging UAD plugins into the FX bin they are not always activated. Another issue is when powering on/off the plugins, they do not always activate again.