I've seen a lot of homemade bike stand and bike repair stands on Instructables as well as other places on the internet over the years and have tried my hand at a few.
I used to have a Park repair stand, which I consider the top tier. I should never have sold it since I bought it cheap on craigslist. But, I had to make room for more bikes and more projects.
What I have not seen on any homemade bike repair stands is the kind of quick-release clamping feature that you find on the Park stands as well as a clamping mechanism that can be rotated to hold onto a sloped or horizontal top tube as well as a (vertical) seat post. I also threw in height adjustment. The only thing it doesn't have is fold-ability. I could add that later by changing out the base.
So that was my task to investigate with this Instructable.