The entire weight shifting control concept is weird not trustworthy at all,especially in the roll axis. Center of gravity moves out, as soon as he rolls, which increases roll rate until he has rolled over by 180°.
Pitch axis also isn't stable, because the engines don't have any V trust vector, similar to aircraft that have dihedral wings.
He probably has much higher chances of flight (and survival) if he buys 2 more engines with propeller and goes with the classical quad copter configuration. Depending how quick those engines react to throttle changes, he could either use throttle, variable pitch propellers or spoilers in the airflow to control that thing like a classic quad copter.