I think there are other reasons to have the lights-on, daytime walk-throughs; the ability to test houses out on kids is only one of them.
I also would question the effectiveness of using a scare zone as a test for a maze. Even when the terror-tories are fully staffed and operating as intended (a rare condition), there is a world of difference between a busy park path with a few actors and some decorations and a dark, fully-immersive house full of monsters. Generally, you can avoid the actors is a scare zone and I have rarely felt that build-up of anxiety in a terror-tory. The houses are designed to make a guest feel trapped and the intensity is designed to increase as you proceed forward.
I also would question the effectiveness of using a scare zone as a test for a maze. Even when the terror-tories are fully staffed and operating as intended (a rare condition), there is a world of difference between a busy park path with a few actors and some decorations and a dark, fully-immersive house full of monsters. Generally, you can avoid the actors is a scare zone and I have rarely felt that build-up of anxiety in a terror-tory. The houses are designed to make a guest feel trapped and the intensity is designed to increase as you proceed forward.