Train station management at half load

The train station management is pretty good at enabling us to request a train when the module is completely full or completely empty. However given that a station module holds 240 while a train wagon holds 120, we should be able to request a train when the module is at least half full or half empty.
For example to manage trains automatically I set a mining station to request train only when all modules full (don't waste train resources going to mines w/o products). All modules fill to 240 and a train is requested. The train comes and load lowering all modules to 120 (which start refilling). Once the train leaves even though the modules could fill another train immediately at 120 (plus what has been loaded by belts while the train was there). In reality I have to wait until the module actually fully loads to 'request' another train and wait for the second train to arrive. Waste of the module storage 240. A train should be requested immediately with the request setting at module at >50%

I was going to suggest the exact same thing. This is my most wanted feature at the moment. And I think it makes lots of sense.