NN trained on uniform cluster sample: overview of mass estimation on eFEDS simulations using our deep ensemble trained with class weights such that the effective mass distribution is close to uniform, illustrating the robustness to uncertainty in the underlying mass distribution. Left: mass scatter between predicted means and masses from the simulations on the training set. The colors indicate our predicted standard deviation. Middle: our mass predictions on the test set. Right: comparison of the residuals and distribution of standard deviations in our test set mass distributions between our normal training procedure with masses distributed as shown in Fig. 2 and our weighted clusters. The distribution of our error estimates shows a mean uncertainty of 0.228.