Looking for a very compact train unloader that fits within a given footprint and can unload a full belt from each wagon.

[Mashaa]

Hi, I am currently making a blueprint book that I want to share with others later, but one specific task has stumped me so far. I need to fit a train unloader that can fit into any of my grid-based station slots, but still unload a full belt from each of 4 wagons. The problem is, these slots are very cramped, so none of the usual unloader designs work. Moreover, different slots have different spatial constraints, but I want one design that fits all, so as to make using the blueprint book easier. My current design for the unloader manages on average approximately 90% full belts by using circuits to organise inserters while fitting inside all slots, but this doesn't feel good enough.

Here's a screenshot of how that currently looks: https://i.imgur.com/37DXE0a.png

I feel like it should be possible to reach 100% full belt throughput with this design by improving the circuit logic, but that is beyond me. Failing that, I would be happy with any solution that fits the grid, even if it's an entirely different design.

And so I ask the circuit and belt wizards among you to help.

Here's the scaffold with 4 slots for stations: https://factoriobin.com/post/08088e

Here's the unloading station as it currently is, align it by the chain signals to fit it into a slot: https://factoriobin.com/post/2naprt

All help appreciated! This problem stumped me for hours now.

[Mashaa]

I ended up solving this problem.