If you have a blueprint that only requires 4 units of materials for manufacture, it seems that researching material efficiency to the max of -10% materials required would do nothing. 4 units - 0.4 units will get rounded back to needing 4 units.
BUT… what if you plan to do 20 runs? Suddenly you need 80 units and 10% of 80 is a big enough number that you could actually save on the required materials… assuming the game uses the same maths that make sense to me. 80-8=only 72 units required. Unless the game just decides that each run requires 4-0.4=4 units, And 4x20 = 80. So 80 units still required even though you bothered to research ME to max.
Which way does Eve Online calculate this? Can there be a benefit to researching the ME when the required materials is only 4 units or less?