Sorry I never wear belts, they have only caused me problems.
My educated opinion is orthos, physiotrists (physical rehab MD's) etc have absolutely nothing to offer me. If I listened to them I would not be lifting at all as they recommended full disability for me years ago. It was doing straight leg deads and squats (against their warnings) that has made my back comfortable. I use to have excruciating pain - if I listened to them I probably still would and would be handicapped. They have good things for many people I suppose, but they are only an obstacle for me. I could just barely deadlift the bar 6 years ago, and now I can do 365 for a set of 10 - they just tried to handicap me first through fear and then through wasting away from inactivity. Pretty much I will always do what they tell me not to do for as much good as their advice has done me.
I may try and erector suit then, it is supposed to be like having "an extra erector" muscle.
I know Karins DD squats suits and bench shirts fit very loose - you can get 2 fingers inside the bench shirt arms easily and probably a fist inside the squat legs. They have to fit loose for the principle of leverage they are based on to work. They are supposed to need no assistance to put on and take perhaps 30 seconds to slide into them.