one way to filter a lane could be to have 3 filter inserters on each side of a conveyor which place the items onto another conveyor which feeds back onto the first one, it kinda looks like an upside down trident.

One of the ideas for the logistic robots we had was that they would use some sort of energy (like batteries or so). And when running low they would need to find the closest "hangar" where they would recharge their batteries. i like :D it also gives the logistics robots a finite range, you...