Cutting 2mm aluminium

Are you running adaptive toolpaths or slotting? You should be able to cut much more than that on an X-Carve. If you’re workholding is good (superglue and tape), I can’t see why you wouldn’t be able to cut the full 2mm with a good adaptive toolpath.
I was going 3.5mm in this post, and that’s on a Carvey.