Short answer, you should go with the second/bottom signature.
Long answer, advanced MPA allows you to “seed” the Signature Values, while Extract actually runs through and calculates MPA second by second using the seeded signature, and then making small adjustments until the proper signature is extracted. This is generally only needed if certain signature parameters are dramatically off (like if Peak Power is 250+ Watts low, or if threshold is significantly underestimated).
Mathematically, it’s possible to fit almost an infinite combination of signature variables to the data, which is why it’s important to have accurate Peak Power/HIE numbers. However, once an accurate PP/HIE value is known, it dramatically narrows down what the proper signature should be.