The parameter t should serve as an indication of the user-preferred risk level when it comes to selecting potentially infeasible experiments. For the FCA function, smaller t indicates more risk, and larger t indicates less risk. In our experiments, we choose to use t = 0.2, 0.5, 0.8. The reader is referred to SI Sec. S.1 A 2 for further discussion about the constrained acquisition optimization subroutine in Atlas.