In the case that the draw stream binner is not operational here yet...
This kind of reminds me of Kyro 2 back in the days, the first tile based renderer for the desktop pc market. It had far lower fill rates than the geforce 2 but it was able to keep up nicely.
The draw stream binner is different from the primitive shaders that needs to be coded for.
There is, i noticed not a lot of information on the draw stream binner from vega.