The "emergency brake" (handbrake ) on Omega was just parts left over from late 1980s Carltons ,senators
try using it above 2 MPH and it will just groan at you for disturbing it , or grenade to give your emergency stop attempt a metal grinding sound track
On my first Omega I used the handbrake at speed .... to errr...... change direction. It worked as intended but it was an auto, and it's fair to say that an auto does not like being stopped instantly. I never did it again.
I never noticed the auto complaining too much - though obviously RWD - but never found an Omega with the same instant grab needed for such 3 point turns, it always ended up being a bit half arsed.
Now my last Rover, that was perfect on the handbrake. So much so, it was usually used to line the car up properly for carparks. And in the 116k I had it, I never, ever touched the rear brakes on that, just tightened the cable once.