If you look at Deadlocks stacking mod you will see that a container holds the same amount regardless of if an item is stacked or unstacked. I imagine he did some math in the code that sets the stacks size based on the stack size of base item. In your case if a barrel holds 50units and your containers hold 500 that means instead of 10 your containers should stack to 1. This prevents abuse with things like warehouses. Is this something you would be interested in adding or making a toggle?
That was partially the objective, a mk2 barrel so to speak. I intended for one slot/one stack of totes to hold 1000 fluid, a step up from barrels being 500.
