From my own testing of rocket part, it does NOT matter what the rocket part recipe output is for a rocket silo. In fact, even if you were to set the result count of the output to 50 rocket parts as a result of the craft, it doesn't result in the rocket being done in one craft. It still takes 50 crafts of the recipe to complete the rocket.
So, if you want this to work as you intend, what you need to do is create a rocket-part to rocket-part recipe that crafts nearly instantly, and have another machine actually craft the 2 x rocket parts that you would get out of the input ingredients. It is annoying that the rocket silo works like that.
The other alternative is to make an Aquilo exclusive rocket silo, that has its recipe fixed to the Aquilo rocket parts recipe, but then reduce the number of "rocket parts" needed to craft the rocket to 25. Recipe for that silo could just be a simple conversion recipe.