I think that the non-static metasound nodes comment refer to things such as the mixer node that has variants and as such may expose different vertex interfaces, but I think that when a node is registered they’re all ‘static’, I looked for examples of metasound nodes that are not completly static either in the engine code or elsewhere and couldn’t find any, really the only metasound node that exposes anything other than the k2 pins is the float input node, and this one uses a different slate widget.