Judging by the location of the acquired set of COFs in PC COF space, MFBO explores diverse regions of COF space, yet concentrates its COF acquires in the regions containing the highest performers. Interestingly, each high-fidelity simulation in a COF was preceded by a low-fidelity simulation in the same COF. This suggests that the MFBO algorithm is cautious to conduct expensive high-fidelity simulations and conservatively utilizes the low-fidelity simulations to explore COF space.