Interesting but I don’t think it will work.
Steel requires specific atomic structure of Iron, Carbon and other elements.
It also usually requires forging to place the stress patterns into the metal structure.
Kind of the difference between using stamped metal fork and a forged metal fork.
You can FEEL the difference in strength.
It might work for a pedestrian bridge. Not a lot of weight on such a structure.
It will be, in effect, all weld bead.
Not as strong as forged steel, for all the reasons you mentioned, but strong enough.
Most structural steel gets rolled. Some gets quenched. Where do you get forged (heating combined with hammering)?
My thoughts exactly. This project is doomed. And if it is completed, the pedestrians are doomed.