From what I can gather, the train stop will fill equipment grid with items from the 'Equipment train stop templates' chest.
If an any item is missing from that template, it will request a delivery of the entire template list of items. This causes extra requests for items it already has. In trying to fill locomotive equipment grid with Two RTGs and Six Engines I noticed when I was short on RTGs, the station would request an additional 6 engines every time a train passed over. (even though it had PLENTY in the chest already)
Its a great system, I just think the logistic request needs to check to see if the items already reside in the chest before ordering more.
