I can confirm that the option is working as intended and as described. Downloaded XCom: Enemy Unknown and our latest trainer, have a scan exclusion created in Windows Defender and ran the trainer with admin rights.
As the instructions say: Be at the base and general overview, have some item building ongoing in -Research-, go to -Reasearch-, press option key ',' (comma on the main keyboard, not the Numpad, next to M), hear activated and press ESC before the option deactivates automatically after 2 sec.
Each time it gives 1000 engineers.
Okay for those that are interested I have sorted out my problem. What I figured to do is press the Numpad 0 key and then Tab to the soldier I want to affect and then press the Numpad * key. When I tab away from the unit I have just changed and then tab back to it I can see that the units health has increased. The all I have to do is activate any other barracks option I want making sure to press numpad * after using each option.