We’ve covered this before, but the TL;DR is that the Proofgrade settings will not work much better than a random number for your “very similar” material, so the only thing we accomplish by sharing them is a bunch of support tickets when it doesn’t work.
Our advice for non-Proofgrade material: do what most non-Glowforge laser owners do. Research a lot and dedicate plenty of time and material to trial and error.