Bondage Bench

I have an idea for a collapsible BDSM bench that I've developed as a concept and crudely engineered. I am about to build my first basic prototype by welding aluminum tubing and creating a rough version. I need someone who can help me improve any engineering as well formulate alternative mechanical solutions to improve the functionality and lower the cost to manufacture while helping me to create a 3D mechanical drawing for use in manufacturing. I need someone to help me consider alternative materials where it makes sense as well as improving things like locking hinged legs, the use of bearings on a rotational arm, and how adjustable modular components can be more effectively incorporated. It will work not unlike many modular home gym equipment systems work so there will be attachments that are currently designed to be attached via locking pins and an adjustable arm using a spring plunger.