I am installing a Saniflo upflush self contained toilet in my basement. This model does not need to be vented. I have seen folks say it is ok to have an upflush toilet discharge into the 2" horizontal waste line before it drops into the main stack. I have seen others say that is not OK. I have plumbers over the years tell me both ways when looking at my plumbing. If this would be suitable, it would save me drywall work and make the install quicker than running the discharge to the stack. The plumbing looks something like below. 2" waste line above where the toilet is going, 1" discharge coming up to it and then it all drops into the 3" line and to the stack. What are thoughts behind discharging to the 2" line?