It is true that it is slow, but keep in mind, in vanilla you have to create 100 'parts' for the rocket, and with my mod you only require 1 'rocket' to assemble, that's why the recipes are so slow. If you take the silo to produce 100 parts, creating 1 rocket takes the same amount of time.
From that time I derived the times needed to create the ingredients, which consumes the same amount of materials as the rocket parts do (with or without other mods like angel, it stays the same). So that's why it takes so long, as it consumes time for 100 parts (all at once). I know it is slow, that's why I am maybe considering allowing efficiency and speed modules on my assemblers.
Kind regards
lovely_santa