Worst-case excess minimization provides a stabilizing value sharing mechanism for energy communities (ECs). It, however, takes much time to solve the problem especially in larger ECs with tens of prosumers. To alleviate the issue, this paper proposes a modified worst-case excess minimization problem which is faster to solve. In this paper, the problem is formulated for individual time slots, e.g., hour by hour, instead of solving the problem for the whole study horizon. This enables modifying the problem by defining new constraints as well as removing unnecessary variables and constraints. By doing so, the minimization problem can be solved faster without sacrificing the accuracy of the simulation. The proposed method is simulated, and the achieved results are compared with the original worst-case excess minimization problem. Based on the results, the proposed method performed significantly better than the original.