Ya you can definitely make one. The Blend node is an "atomic node" which are fundamental and optimized nodes. SD allows you flexibility to build up custom nodes yourself using simple nodes.
So I'm learning SD currently and I'm finding it odd that the blend node only has two inputs. I'm thinking there has to be a more efficient node to this with. Why not just be able to "+" to add more inputs and select the blending mode for that input. Heck even if you can only select one mode for the whole node. Am I missing…