SSDI is the disability based on what you paid in. I have been considered self employed for years. I have gotten 1099's which I had to report and I have reported cash as well. I'm now glad I always reported all my income. Even though it sucked at the time having to pay the full social security on my own (self employment tax) I am actually expecting my first SSDI deposit at the end of the month so I'll start getting it back. It's actually going to be enough to cover most of my current bills. Though with ESRD i'm sure more bills will be added along the way.
They approved me very quickly back in May so the 5 month waiting period ended at the end of Sept. so my first payment will be for Oct.--minus my Aug through now medicare part B that I just got approved for.
I stated my kind of work on the app and of course SS has my previous records as well and everything went through fine, after all, this is based on what I have paid in over the years. So in that sense it really shouldn't matter if you've been self employed or employed by a company.
Now I'm curious how it will be affected when I return to work in a few month's, as I'm going to try to get my service business going.