Very cool! Yeah, just leave the computer on. It draws very little power, just the CNC needs to be off. Also, don't hesitate to add more tabs, if I'm worried, I generally just throw another two on. I'd say about one per foot of piece circumference with two minimum is plenty. Tabs are easy to fix, just take a chisel and hammer to them, really easy to get the piece out no matter how many you make. There's a screwdriver/chisel on the pegboard, or I might have left it near the CNC.