There is a great guide to the custom settings that Glowforge has written up. It’s linked in number six here called working with manual settings:
There’s no one right answer for something like a macaron, because they are very much an inconsistent material to work with. Depending on how someone bakes it or what the actual recipe is, it could have pretty different properties. I’m afraid you’re just gonna have to test a little bit, and unfortunately that means that you’ll have to eat a lot of the test materials, which sounds just awful 