I have heard 7 seconds from your competitor's stage to your stage, but no official pre stage to stage time limit. Here is all the 2016 book says:
A reasonable amount of time will be permitted for drivers to
stage. The time limit will be determined at the sole and absolute
discretion of the official starter. Failure to stage upon the starter’s
instructions is possible grounds for disqualification.
I'm a new racer in a new car, too, and there is way too much going on up there to play games with anyone.
Dale