I think the actual % attributed to the aug (if the idea was actually worked on) should be at the discression of the developper working on it, and I hope this developper has played FC extensively to dose the attribute with consideration.

It is easy to merely state numbers on a suggestion, but it is useless, numbers get shifted constantly during testing. If a hard number would be put in without testing, things would become unbalanced.

On another note, if this is added for end game (or t20) augmenters it would be added for t10 and t15 augmenters as well. If it were me working on this idea I would make the new augs (the one with the slave stat +%s) optained through BPs and built from the regular class augs just to make it a tad more annoying.