Yeah, don't take this shortcut. Take the time to learn why the reasoning works the way it does and reason your way through it. Why settle for a cheap trick when you can do it properly and guarantee yourself the point?
you're definitely not alone. There's no shortcut really. Gotta know the concepts like second nature and have very fast timing w/o sacrificing accuracy. You'll get there, ur very determined.
I would save them until the end or until after you get some analytics from your PTs. I think they are moreso just a shortcut for reviewing specific question types after the fact if you are struggling on a question type.