I render an animation with EEVEE and every frame takes less than 10 seconds to be rendered (in 4K). I also output normals, AO, and other images in the same render (using a File Output node). Unfortunately I also need a position map (P-map) and a velocity map of the same render. I would like to have it in the same render, but also having an additional (fast) render only for these it's fine. For the position map, I found that I can have it by using a special emission material with a position information as input. As for the velocity map, it seems that EEVEE is not able to output velocity maps (?).
My first attempt was creating a new scene, linking all objects from the first (main) scene and using Cycles in this new rendering, with a material override for the P-Map and with a velocity pass that outputs the velocity I need. The only problem is that since I am using Cycles (although only to receive information, not for actually render), a single frame takes no less than 30 seconds. Is there a smarter way to receive these data?