The acquisition function is used to select the most promising evaluations to perform next, i.e., which reaction profile to acquire with the help of our automated reaction profile computation workflow. Acquisition functions are typically derived by considering the mean, µ(x), and standard deviation, σ(x), of the surrogate model predictions, either by considering an ensemble of ML models trained on various distinct data splits, or by analyzing the distribution of the individual estimator predictions (e.g., when random forests are selected). In this work, the upper confidence bound (UCB) has been used specifically: