From a programmers point of view, it seems to me that the VST's should have a global constructor so that not every instance of plugin have to load what I believe is the set of names inside PB. Second instance would go quicker. But first instance still would need to do this, unless cached locally from last use or something.
From what I remember using PBC it's that time is take to load that data, you are experiencing causing a delay. Time until color goes orange for presets in PBC as connected.
Are you dependent on these VST's, or did you try to make an instrument definition in Cubase?
Disadvantage is that you need dedicated audio inputs from that instrument, at least in Cubase Pro 9.5 I used 3-4 years ago. I manage to fix that having RME soundcards, which could duplicate one input to always be able to use it through a patch bay with different synths anyway.
Advantage is that you just press Freeze to render audio into Cubase just like with a VST instrument.
But overall left that approach to keep it simple.
I don't use any of that VST stuff for external midi gear, just regular midi in/out.
Not many hardware manufacturers provide VST's anyway.
But I do 99% live recordings, and no programming, so might not be doable for everybody.
Just trying to give a different approach to it....
