Complex sentence: The "official" name for the engine is the 109-006, and it was often called as the HeS 006; development ended just as these names were being introduced by the RLM, so HeS 30 is much more common.
Split into simpler sentences: The "official" name for the engine is the 109-006, and it was often called the HeS 006. Development ended just as these names were being introduced by the RLM, so HeS 30 is much more common.