I laughed when I read these choices.
Lights Motors Action??? They seat people even after the show has started, and I've never heard of a full stadium for the show.
What exactly is a FP going to accomplish here?
Maybe some special preferred seating section?? Will be curious to know about this if anyone actually chooses this option.
LMA has a long history with FP.
During its first couple of years, they used FP for all the performances.
The theater often filled to capacity, and guests were turned away.
That doesn't often happen anymore, though.
(I'd expect that it still might happen during Christmas Week, Easter Week, July 4, etc.)
As to how FP's are used at "show attractions..."
Guests with FP must show up (for example) by at least 15 minutes before show-time.
FP guests will be held in one large area.
Guests without FP will be held in another area.
FP guests will be allowed into the seating at (say) 15 minutes before show-time.
After FP guests are admitted, the general guests are released into the theater until all seats are filled.
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All that said-
They are in process of adding FP's at all of the parks to a TON of attractions that generally do not ever need a FP.
This will allow/cause unsuspecting guests to use some of their FP+ choices for attractions that would otherwise have a very short standby wait.
But that is an entirely other kind of discussion.