So, Essence Reduction reduces the essence cost by 5%. Bio-Index reduction does the same thing. It says "Apply the total of all similar adjustments as one multiple, not separately."
So if I'm getting Betaware 60% essence cost, and Essence Reduction -5%, does it cost 55%, (0.6 - 0.05) or does it cost 57%? (0.6 * 0.95)
Thanks.

The first example is correct. You compound all the multipliers together before applying them. So with the Essence Reduction surgery option, you multiply the Essence Cost by 95% for Standard, 75% for Alphaware, 55% for Betaware, and 45% for Deltaware.