Looks quite a neat solution in theory but although I'm not a mechanical engineer I have concerns.
Your scheme means metal-to-metal contact over a very small area at a point not designed for this. Possibly at a single point if welds are not exactly the same height both sides.
Principle of leverage also means that the force of the return spring is magnified as the weld area is much closer to the stand pivot point than the spring.
Concern may be unfounded but I suspect that over time something may wear or fail, either the weld or the frame tube where contact is made.
Personally I wouldn't take the risk, I'd go for a bracket with a rubber stop as others have already suggested.
