Yep, I nearly sliced off a junk of my thumb early on in my build with the necessary but cursed Xacto.
The doctor at the hospital was a little weirded out by the deep and severity of my cut. While he stitched me up he asked several different times how this happened. I really wanted to tell him - dude like I really wanted to slice off each digit at two inch chunks at a time. But bit my lip so he wouldn't give me a sloppy scar...