MFS has a very sound background in this stuff so I would counsel heeding his commentary. For my thinking, Vmc/Vmcg are potentially hazardous certification animals and, as line pilots, we are better off giving them a moderate berth where feasible. Better to leave the risky stuff to the QTPs of the world (who are trained in managing those risks).
Does anyone know how to get the book “Jet Airplane Performance” of Lufthansa Consulting
I don't think I have read that particular book but there are others of a similar vein on the net, eg Performance of the Jet Transport Airplane etc by Prof Trevor Young (Wiley), and others. Also the Boeing Performance Engineers Manual and the Airbus Getting to Grips manuals are a good read. These can be found on the net.
you have to use your feet to block the student's pedals and create a fake vmc.
In a similar vein, a colleague had need to pick up a GA twin endorsement prior to renewing an instrument rating years ago. His experience didn't warrant much of the stuff commonly done on light aircraft. So, when the mentally programmed instructor set out to have him demonstrate Vmc (which you can't really do, anyway) he held some rudder in reserve. This perplexed the instructor who then proceeded to demonstrate the exercise. My colleague held the rudder blocked to keep things sensible and the instructor went home quite confused by what he had experienced ......