So, I have been cutting with the 5mm underlayment and so far so good. After a few tests and trails, I settled on these settings for pretty consistent cutting:
Power: Full Power
Speed: 130
Focus Height: 0.198"
These settings can probably be improved on, but this is what works. After transporting the material to a drier climate, a lot of it has a little bit of a warp. If the material is flat, then you could probably go faster.