Your welcome. But you should not need 2 passes to cut 2 mil vinyl. Add a little force. First make sure you set your blade depth correctly. And only cut what you can weed at 1 time. Because you are correct, vinyl will self heal.
This is correct way to set your blade depth.
To start with, you should set your blade depth correctly, by taking the blade holder out of the machine, and firmly cut across a piece of scrap vinyl, you will be cutting. You should only be cutting the vinyl and barely a mark on wax paper backing, Adjust blade to get there, Then put the blade holder back in machine, and use the force of the machine to get there, same results, only cutting the vinyl and barely a mark in wax paper backing. You should just barely see and feel your blade tip out of the blade holder.