As you discovered in the program list, there are some ROMs that support tournament mode on the PE+.
There's an old post about it
here. On games that support it, the procedure to enable/disable tournament mode is:
PE+ Tournament Mode:
1) Turn and Hold the Jackpot Reset Key
2) While Jackpot Reset Key is held, press the "Change Request" button
The game should flip between tournament and standard mode (and vice-versa). You do not have to finish the tournament countdown clock, you can do it right away.
I don't think you can do it with any of the multi-game sets, I think it is only available for dedicated single game setups.