The red line overtakes the blue line just before the very end, so after taking the 300 missions, the red path results in more total standing gained, which is why I call it the best case.

The multiplier I'm using for diminishing returns is shown in the image below. 1.0 up to 600, then ramps down to 0 at approximately 1007 (based on experimental data taken in-game).


The argument that other games have a more tedious grind is a silly argument to make. The fact that VO doesn't have an excessive grind is one of its strengths.

EDIT: For accurate calculations, you need to be working on the 0 to 65535 scale. The reward value after accounting for diminishing returns gets truncated to an integer on that scale.

The reward value after accounting for diminishing returns gets truncated to an integer on that scale.

This is the reason why it's simply impossible to get +1000 by doing certain missions. The faction gains they give at that point get lost to a rounding error. :(