Couldn't get any easier than that.
I have used it. Works great.I use the Keyhole Toolpath Gadget that is built in to Vectric VCarve Pro and Aspire ( VCarve Desktop may not have Gadgets). Once you have it configured with the size of bit you are using and the orientation of the keyhole, it is an easy cut. It saves your settings so it is ready the next time you need a keyhole.
Can't get much easier than that.
Thats what I meant, ramp downward then return ramp back up.... I've done a couple where I used the fluting toolpath to start 1/4" deep, ramp another 1/32" or so, then ramp back to the starting position before retracting from the wood. That was when I needed the screw to get tighter as it slid up the keyhole slot.