A bridge of conveyer belts that vertically crosses over another belt lines may add possibilities of factory set up.
Another thing to add, it’s hard to use one INPUT line into multiple machines at once (since it needs more splitter and makes it annoying to make them connect)
Some version of crossover belts would be an excellent addition. They could either be full 3D planning with high and low belt tracks that can be placed over/under each other (including up/down ramps to transition between) or it could be a simple unit that never stores a product itself but will move the product from one side to the other whenever space is available