When I called NI about GR4 Sonar they seemed annoyed. This was shortly before the release of X2 (when you guys switched to Overloud for your included amp sim... which of course I had no way of knowing at the time). He was rather rude actually even though the question was regarding me upgrading to GR5 which would see dollars put directly into their pockets.
Kind of like a spurned ex lover. lol
Hosts should be aware of plugin formats and compatibility issues obviously but I think the bulk of that responsibility should be on the plug manufacturers... at least for the more commonly used DAWs which I'd say Sonar qualifies as. I mean if your stuff doesn't work in the environments people use well...
That said I've never had a problem with GR5. I don't own any Waves stuff though. Hope you get it sorted, sharke.