Well, you can only be waiting virtually in one line at a time. BUT, once you’ve waited the required time, that ride reservation changes to “Ride Anytime” and you can get in another line virtually. You have until the end of the day to use that reservation.
So, if you tap into ride A and get a wait time of say, a half-hour, and then you tap into ride B when it says that there will be a wait and when your ride A still has 15 minutes left to wait, then the ride A reservation disappears because you can only be waiting virtually in one line.
But, if you wait until your Ride A reservations says “Ride Anytime” to start your wait in Ride B, then the Ride A reservation stays there and can be used anytime that day.
There isn’t a limit on the number of ride reservations you can have.
Some background info. At VB, everyone gets a taputapu as they enter which is like a MagicBand only better since it is free for everyone and has a screen that tells you stuff. There are taputapu stations outside the entrance to every ride. These stations will either say “Ride Now” or tell you how long the wait is. If there is a wait, you tap your taputapu at that station and it puts you virtually in line. When the time is up, the taputapu screen will say the name of the ride and “Ride Anytime.” If the tapu station says “Ride Now” then you don’t need to use the tapu station, you can just get in line.
As you get in the line, there will be a manned station where you tap your taputapu. That keeps count of how many people are using the ride, and marks your ride reservation as used.