As we've never tried etching on anodized surfaces yet, in theory it should be able to. I will bring some scrap pieces down there next week to try out and see how it turns out.
As for depth, it makes no difference how thick the material is, it's the matter of how deep you want to cut/etch into it. But in terms of what can fit inside, height wise, for etching I think something up to 6" is safe to fit. As for how deep an etch can go, it all depends. Depth is based on the power of the machine and how we set the settings. Usually, we leave the speed % at 100% and power at 15% which is how the etches turn out in the pictures. For a deeper etch, we can switch the power to 50% if we'd like but we'd have to cut down the speed time and would take a while for the etch and would cost extra since it'll take longer.
And also, it varies sometimes for how thick of plexi the machine can cut. 1/4" is the best cut and 1/2" will sometimes cut. So we'll say 1/4" as a safe bet