For unknown reason sometime the stack is not complete I often have 30 instead of 32 items on belt. (this will a full chest of item so it's not a problem of input)
Possibly (probably). The stacking is part of the base entity that I'm making available, not something I'm creating. Are you using belts faster than Turbo (60 Items/s)?
No turbo belt from Space age. Nothing special, did you not see this problem before in your game ? Should be simple to reproduce a chest that have one output loader and 6 input loader of stone, don't know if chest full or half full matter