It sounds like you're mixing lines. That's generally a bad idea for that exact reason. Even if you had an incinerator, you'd need to make sure it's not touching the factory and voiding the output
Yeah if there's anything I've learned from Factorio and Satisfactory its that mixing lines generally are more trouble then they're worth and its more work up front to build dedicated lines for everything and takes up more space but generally much less headaches later on.
