> Granted this is less of an issue for physics where virtually every index goes from 0 to 3 inclusive These days physicists who do tensor-network analysis and

> Granted this is less of an issue for physics where virtually every index goes from 0 to 3 inclusive These days physicists who do tensor-network analysis and simulations of many-body quantum systems (e.g., MPS in 1D) probably use the diagrams more than relativists, and in those cases the indices can come with arbitrary dimensions.