I am uncertain as to if the OP can arrange things to keep the disability benefits. As a legal matter, I don't see the creation of a C-corp as fraud or anything but a legal manipulation of facts to create a benefit. Is that what SSDI if for? No. But, all laws have to be written for the real world and all the world required is to follow the law, not to guess at the law's intent and achieve the intent.
Now, will the plan work? I don't think so. There is a lot more to running a corporation than just filing to have a corporation. I'm not going through all the problems here, but everyone wants money they can control, but not have to be considered the owner of. The plan doesn't happen much because the facts have to be extremely correct for it to work. I have no idea of the OPs plan is going to work. I suspect not, but don't know the business model.
However, there is a program called BOND where the $12K is not a cliff. It costs $1 for each $2 earned over the amount. It is designed just for this situation, to help disabled on benefits get a job which pays them a living wage. It's not a good solution if the OP just wanted to continue to have me pay extra to him forever, but it would certainly solve his purported problem.