Wgilst I remain utterly unconvinced by your need for the belt, it is good to see you pushing bigger stuff around.
Ultimately belts help, no matter how you look at it. I don't need to be wearing it for all my work, however due to my on going lower abdominal twinge/suspected hernia I need to learn to use the belt so that it doesn't aggravate this. Throwing it on for the rep maxes is not the one, so it will go on during my last warmup sets and stay on for my working sets.
I need to make sure that my form with the belt no doesn't break either and this can be learnt and reviewed at lighter weights still.