So its a very good design for the most part. In my use of it, I have only identified two potential problems. One is that the sulfur has to be manually managed. The fertilizer II does not use all of it, and it creates a flaw. I have to keep some sulfur in the storage because otherwise fertilizer I does not get used up, meaning ammonia backs up, meaning sour water backs up, and then the entire system jams. So i cannot take all of it out. However, I also cannot leave it all in because then the same thing happens as sulfur backs up. I have done some work to find a potential solution, and i believe i have found one. you just want two storages, linked to two different balancers. The first is priority to the internal system storage, the sulfur for making fertilizer II. The overflow goes on to another storage in priority for use in other projects, rubber, etc. If this overflows, there is a back-up burner attached. This would solve the problem. The problem is your build is such a maze of pipes (i honestly don't know how you did it) that I cannot add this fix to it in my world.
The second problem is with heavy oil. The system does not currently prioritize turning heavy oil into the resource (diesel, naptha, fuel gas) to be used first. This results in me constantly having to watch it and flare it off when it gets too high because the system would rather turn crude into it, which would be fine, if it were not for the fact then the heavy oil backs up and jams the entire system.
Other than these problems, very good build, i use it a lot.