I hope a way could be found to make it happen: 4 ball lock.
The imbalanced 5th-Ball Dimension - Wizard Multiball : Time Travel
1. Locking one ball on one side, then a second on the same side. Now two on one side.
2. With the post up, locking the third ball in behind the vacant drop target/side.
3. Two on one side, one on the other side, now post down, targets both held up (locked closed captive ball area). Need to "knock" all 3 balls to one side.
4. With the Closed Off loop, the game logic Could conceivably know that there are still three balls trapped within the horseshoe?, just that All are on one side (acknowledging the "ghost" ball in the three high position), due to the 2 empty positions on the other side.
5. With the fourth ball, knocking drops does not let them fall or release multiball, unless the balls are All on one side with post up. The player must hit captive balls so that all balls get to one side. Drops are always forced up (by long opto) during this phase.
6. After a given time of the horseshoe reading 2 optos closed on one side, and 2 optos open on the other side, the post can raise. After a further time, to ensure no ball is dribbling down back to the vacant side, the vacant drop/lock can then be Enabled, to drop and receive the fourth locked ball in the vacant side.
7. When there are three balls confirmed on one side (when logic "loses" the third horseshoe ball for long enough = all 3 on one side), and post is Up, hitting the Loaded side does not release, but hitting the empty side lets the fourth ball in and locks it there! . When this is achieved there are now confirmed 3 balls in one side and 1 ball in the other side.
8. So three balls now on one side, one on the other side. The game reads only three balls in the horseshoe, but logically knows where the fourth "ghost" or "lost" ball actually is; in the horseshoe (this is of course confirmed by the empty ball trough, as well as lack of any other playfield switch activity).
9. Now there is a 5th ball only left to play with, which pops out of the portal re-entry! This is a Time Traveling Morty, emerging from the portal at an earlier time than when he will enter it, creating an imbalance! ... between dimensions. Limbo.
10. Start 5 Ball Time Portal Multiball!! - by hitting Either Target with the 5th ball, which causes them both (All balls) to drop.
A Success would be: Releasing 5 ball multiball, with first Jackpot being to restore the "lost" (Morty) ball to the top portal (before MB ends) and close the time loop. If you have only 2 balls left in play then the jackpot ends the multiball (5th ball remains in the re-entry), no super jackpots. The One Time there would be an intentional unclosed portal loop; To restore the staged ball from the Wizard Time Travel 5 ball Multiball.
A Simi-Fail would be: Releasing 5 ball and losing all but one ball before shooting Portal. In this case equilibrium is restored, but there is no jackpot and ball might be re-launched.
A Semi-Fail would be: Not releasing 5 ball multiball before draining. The game drops the single ball from the horseshoe (Jerry Lol), then you get a hurry up, a chance to restore equilibrium to dimensions and continue your game, but it becomes a Very Risky Time Travelling JERRY!. Perhaps as a MB restart chance? .... Rick: "Go for the damned Portal NOW, Jerry! .... or the Universes All End!" (game over). For re-start it's now Morty that needs to be locked in the vacant horseshoe side, so that Jerry can get out of the time portal and free everyone! Lol ... Jerry will make it RiKsy!
The balls could be representative of : 1 Rick, 2 Beth, 3 Summer, 4 Jerry (loner on one side of horseshoe lol), 5 Morty time traveler...
Time traveling Morty balls mission is to free his family from the trap. So, if the 5th ball is shot into the portal without releasing the rest of the family, then the same 5th ball is re-entered (but now with a subway delay obviously), repeatedly, until the mission either succeeds or fails.
Fail: No restart, imbalanced dimensions, drained balls.... universes All End. Game Over
I know it might give Eric and Scott nightmares to create code for something like this to work.... but just thought the logic looked possible
... and something that could be pretty cool!