Re: Velocity Envelope duration

[Stephen Crye] "If I have already squeezed it by 12x, how can I squeeze it more if I don't render it to an intermediate?"

Save the sped up event as a veg file (let's call it speed-1.veg).
Import speed-1.veg into your project ("nesting" it) and apply the velocity envelope and do the Ctrl+drag think to it.
speed-1.veg was sped up 12X.
Applying these same techniques to it again speeds it up another 12X which means that your original event is now sped up 144X with no need for rendering to an intermediate format.
BTW, to avoid horrible ghosting/frame blending when doing this, I usually right-click the event, choose Properties and select "disable resample".

"And, with a bunch of "raw" 12x squeezed clips in the timeline, rendering a long project is suuuuper slow."

That's the biggest drawback to nesting files so an intermediate may be a better choice. Only you can make that decision.