TJ Walker (YouTube video) explains an ethical "cheat" for public speaking: a one-page cheat sheet that contains a handful of key points and brief reminders of stories/examples so the speaker can deliver an hour-long talk without memorizing. He emphasizes making the sheet a single page in large font so it stays discreet (no page turns, no fiddling) and reassures viewers that using such a cheat sheet is acceptable and unnoticed by audiences.
Chapters
I want to teach you how to cheat when you have to do public speaking. Now, let me explain. I don't want you to do anything unethical or illegal. This is an ethical way of cheating. You may be thinking, oh, I get nervous. If I have to give a speech or I've never given one, I'm going to be really nervous. I'm going to forget what to say. Guess what? You don't have to memorize. You don't have to have a perfect memory. You can do what I do. Even to this day, I cheat. I use a cheat sheet. This is everything I need to know in order to give an hour long speech. What I've done is I've put it down to just a handful of key points and then a few reminders of the stories and examples underneath it so it fits on a single sheet of paper. Now, the secret to using a cheat sheet is it has to be on a single sheet, large font, so no one ever sees me picking it up. No one ever sees me going to the next page. No one ever sees me fiddling with it, putting on glasses because I've made it in large font. There's nothing wrong with using a cheat sheet. Your audience won't know and they won't care.