Bondage Bench -- 2

I'm working on a collapsible BDSM bench that I've developed as a concept and crudely engineered. I'm just finishing up my first prototype and have learned a few things along the way (which is why you build prototypes ?) I need someone who can help me improve any engineering (including calculating load requirements) 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 I believe I've discovered that I will be forced to use some steel components to ensure structural integrity (i.e. joint, hinges, base of attachments). I will need help assessing alternatives for locking the collapsible legs, consider the use of bearings on a rotational arm, and the effective attachment of modular components. Those components are currently designed like rudimentary gym equipment via a series of holes and attached using spring indexing plungers. I've had some issues with the ease of attachment (some of which may be lack of precision equipment) so I will need help considering certain details in regards to size of plungers/holes while considering that each hole is further compromising the structural integrity of the bench. In working on the prototype I've determined that the support pieces may need to be steel because of the softer nature of aluminum but could use some analysis on the use of cast components versus fabricated ones as well as understand and analyze the consideration of using special aluminum extrusions to meet load requirements if necessary. Like with anything that is designed to be compact or collapsible, there is a goal to keep the item as light as possible while still meeting the structural demands. I'm looking for someone who can NOT just produce a 3D CAD drawing and give me a theoretical product, but I need someone who can potentially improve the design while helping me minimize the costs of production and logistics associated with the project as the whole. Given that the purpose of the item is sexual in nature, it may be necessary to share examples of similar items that may have adult content but I will do my best to edit and remove any graphic portions so as to not offend. I have done some simple designs in tinkercad that will help illustrate what I'm trying to accomplish as well as being able to provide some pictures and commentary on the prototype I'm working on. I will provide this information only upon awarding the project.