Ahhh tbc, Jedi Master, you are sent to test us! My ten pence worth (lets see if I was listening to you!)
Are we talking about the cable/rod aft of the diverter plate letting go and the control quadrant in the cone giving you a full cone right condition but still have control of the fan? If we are then it will depend on what stage of flight you are in when it goes on what you will feel.
Before I start, I will just say that all of this will depend on aircraft all up mass (heavier more torque reaction), wind strength (weathercocking/TL) and density altitude (as pushing air) at the time of failure.
It is going to be a balancing act of torque reaction + thruster vs coanda + VSCS at various speeds to give you directional control.
I will just add that talking about turning off the VSCS is a red herring. The VSCS on the 902 has no direct pilot input and is controlled by the magic boxes under their own control laws. They tell the fins what to do to aid directional control and stability, so best let them get on with it and let it help you and not disable it's assistance.
If we look at the division of control authority v speed
"TL = Translational Lift"
In the hover, into wind. As the thruster has only 30% authority the aircraft may start to yaw right but a combination of increasing the coanda with the pedal (natural action) and weathercocking will keep you straight or the yaw rate will be low enough to touchdown. A quartering wind from the left will assist to keep straight.
About 80kts as the thruster has no effect you aren't going to notice anything.
The interesting area will be as speed decreases below 80kts when the fins are losing authority, the thruster is taking more of the control authority and the coanda is yet to kick in.
As speed reduces further the fins become ineffective, the thruster is taking more of the control and the coanda effect is yet to kick in. This is when the aircraft may yaw right. I don't think the aircarft will yaw violently as the thruster doesn't have the power to move those slabs of fins through the weathercocking effect. As speed reduces below TL the coanda will have more say and counter act offset thruster and give you the situation in the hover.
So what would I do? Firstly at a safe height with a quartering wind from the left I would bleed the speed off and see how bad the yaw gets and see if it straightens itself below TL. You can always fly out of it and recover above 80kts and try again.
Once happy it is all controllable I set up to a clear area with a large hard surface and a quartering wind from the left and give it a go. Probably aiming to come to a higher than normal hover and then descend vertically.
I would also make sure someone is there to video it for YouTube!!
I await your comments Master!
FNW