That small piece of fabric does not act as a fail safe it is there so if a evac is required and the seats are released they do not all release at once. On B&M and intamin multiple rows get unlocked at the same time and so the belts are there to hold them so 1 row at a time is removed. Gertslauer have individually unlocking seats so they do not need seat belts. As for hydraulic seats are considered safe that is true but that doesn't explain why The Swarm has seat belts. The only purpose for belts is in the event of an evac, the ratchet system can not slip otherwise there is no way they would be allowed to have them. You can believe what you want but I am telling you they are there for evac only.