Recommendation
After the preshow and when you are in the barn queue, choose the right side of the queue to get on the first (my fave) or second section of the train.
You seem to see a lot more when in those first two sections and the story is a bit easier to understand.
If the CM tries to direct you to the left side or sections 3 and 4, request sections 1 or 2.
Checked with CMs and two of them said you have one hour once called for your VQ or the time posted on the pass.
Third CM was a bit more hush hush and said there was no expiration after called.
So there is a risk depending on the CM you talk to.
Which got me thinking, there shouldn't be an expiration on VQ because you have no real control of the return time you get and some guests don't arrive in the park until later in the day.