This is a multi-material blend node that offers both an opacity mask and a blending mode for every layer. It allows for up to eight inputs to be blended into a single output.
This can be a heavy node, but if your concern is keeping your graph neat it can be a great tool.
Re-worked how the masks blend and combine. The layers should stack properly now. The limitation is that each layer requires a mask now. If you don't need a mask, you can add a white Uniform Color to the mask inputs.