This is a suggestion …
Could be called seamless rendering - background render - flexi-freeze etc…
A feature available to be selected on each track, probably enabled on all by default that would render the plugin chain automatically into the audio when the track is deselected.
No need for volume or non plugin automation to be rendered.
That stuff uses almost no CPU.
The uneffected original audio would be saved in the background , and could be called up if needed.
The plugins in the chain are back to real-time processing if one of them is opened up using the original audio so that you can hear the changes real time.
When the track is de selected again it is rendered slowly in the background while Cubase continues working. ie no waiting.
The processing could be real time until the rendered track is done to make it seamless. Perhaps switching the rendered version in automically the next time playback is stopped after it’s ready.
The same thing on group tracks would also be awesome.
We all use a lot of group processing to streamline mixing.
No group audio is shown in Cubase like now, but an audio file could be kept in the background until a change is made in any of that groups inputs or that groups channel plugins.
Vsti tracks could do the same.
You could have huge HUGE projects on a modest computer and it wouldn’t be a pain or take time to deal with ( like offline rendering ) and its much more flexible than freezing and no waiting. No need for multiple computer setups.