A good friend of mine writes plugins. His take on the plugin problem is that often in the development cycles the programmer/devs come to a point where they can take a shortcut or do everything by the book. The ones who take a shortcut because "we don't use that," or "our users don't use that," often leave gaps in code - where the DAW is expecting one thing, the VST just tries to skip it. Consequences vary, but he says "the ghost in the machine" (unforseen, or unintended new issues/relationships in code) are always an issue - but good coding practice can avoid a myriad of problems.
Which makes me wonder if some of the Kingston optimizations weren't actually shortcuts that are now the root of unexpected problems. By which I mean, the shortcuts/optimizations in Kingston may be perfectly good...now we're just being introduced to otherwise dormant shortcuts the VST devs took. *shrug*
I had some weirdness with Kingston, but I've now got it narrowed down to just one misbehaving plugin - the VST2 version makes noise, but the VST3 version is fine.
All that said, the speed increases are impressive. CW seems to be getting everything right...Kingston is hopefully just a minor bump in the road.
My only aggravation in all this is that CW drops a huge update the day before Thanksgiving, and then close shop for the long weekend. I wouldn't want to see their inboxes/trouble tickets/voicemails on Monday. ;-)
(And Happy Thanksgiving)