So does raising and lowering the layers change something visible on the keys or is it that you just have to know?
I have a Moonlander and had to print my layout on paper so that I could glance at it until I got used to it. Did a few adjustments, and eventually settled and enjoy it.
It's not a big deal. I have an Atreus, which has even fewer keys, and correspondingly makes a bit more use of layers, and I had it all into my muscle memory within 3 or 4 days.