Selecting both virtual supply trucks and explicit supply

[HMCS Rosthern]

I notice that if I take a scenario with explicit supply (or at least some scenarios)
1. select virtual supply only and display local supply values, the numbers are variable going lower the further the way from the supply sources.
2. select explicit supply only and display local supply values, the numbers are fixed at 80, as per this rule "In addition, the basic test to determine when Low Ammo and Low Fuel potentially occurs is modified by using a default Local Supply Value of 80.".
3. select both virtual and explicit supply and display local supply values, the numbers are variable going lower the further the way from the supply sources.

Does this mean that selecting both means that the local supply values are not fixed, and the Low Ammo and Low Fuel basic test uses a variable local supply value?