Sample position for a single run is shown in the decision and objective spaces (Fig. ). We specifically plotted the decision space with 𝑄 𝐴𝑔𝑁𝑂 3 , 𝑄 𝑠𝑒𝑒𝑑 and 𝑄 𝐴𝐴 , as these are the flowrates affected by the repair operator. The sampling distribution of the non-dominated points (black square) in the objective space indicates that EGBO with pre-repair achieves a good coverage of the PF, without any oversampling at high 𝑦 2 . Part of these non-dominated points project into a line in the decision space, corresponding to the constraint boundary 𝑐 2 (see SI 2.3). But the other non-dominated points are still sampled within the feasible space. Interestingly, we also note that most of the non-dominated points are located on the box constraints, suggesting that better optimization results could have been achieved by increasing the maximal flowrate values.