Hey ! Thank you so much for the detailed feedback, it is always interesting to smart ways to beat the game :)
It is intended that people find ways to beat it in a way that feels not intended, but works, it is a sandbox and I want players to fins smart ways or even break the game, as long as they have fun it's ok (I fix issues and bugs killing the gun out of it but keep the funny ones in), so yeah, not everything is designed and I know people will find ways to beat the full game I never thought about but that's what's the game is about yes !
The game won't have traditional conveyors but tools will be available to build your own conveyor system, and I'm trying to make it so there is not one unique solution for it and people can play how they want (and if putting all the ducks and other products manually in is the way the player want to play the game, that will be possible, even if that's not the most efficient way to do it)
I have already some different ways to make more profit with similar (but different) to what you described for the quality control, but I designed it as a bonus and not a mandatory way to do it (I'll have a lot of balancing to do haha)
I know with only the demo content it is a bit hard so see where I'm going with this and I hope the full game won't disappoint.
Thank you again for your feedback, it helps shaping it toward something not disappointing (that's what I'm hopping haha)