Cubase isn’t smart enough to do this, if there is any external instrument or external plugin used in the project.
All tracks will be forced to real-time rendering.
Well I can’t remember if disabling those tracks makes a difference, have to try when I’m in front of Cubase again, but probably not.
If it were me, after rendering the external synth real-time, I’d “Save As” CoolProjWithExternalSynth. Then delete the Track that uses the external synth. You don’t need it anymore & if you change your mind you can easily Import the Track from CoolProjWithExternalSynth
Thanks for the help guys… good to know what i have to work around. Thanks for the tip aswell… was also thinking i might export any tracks to be reamped to a different project for reamping. Then i can render to my hearts content in the first project. Will depend on the project i