I agree Morten, and I value your thoughts. however there are a couple of things different about this bar. Due to the installation angle it is canted back so more likely to collapse to the rear than forward. There are also a 1" angle pieces directly welded to the roll bar and 1" indirectly connected to the bar that for the back of the cabin that also would prevent folding forward onto to the passengers but allows it to move backward toward the engine. Other considerations for making the removal is this car is not meant for racing but for street use or DE events. This car is meant to be an homage to a road car which is why I removed as it interferes with the rear clam and angle pieces that hold the slam catch assembly I have yet to fabricate and install.
If I wanted to seriously track the car YES I would put a down bar back in but INSTALL fuel cells as I am more scared of fire than roll over. I rolled a Healey 100-4 at TWS 4x before stopping on the roll bar, having to un buckle and crawl out before the corner workers could get there. I know what it is like and also how much racing 5 point belts will stretch. So I know the value of a good roll set up as it saved my life.