Since the Maya team noted that they need this field in order to derive the node name (with correct capitalization and word break) to show in the editor:
since the name of the node is open_pbr_surface, it will require custom code to turn it into "OpenPBR Surface".
uiname metadata is already in the MaterialX specifications in the "Custom Node Declaration NodeDef Elements" section for MaterialX 1.39 and I see this as well in the old 1.38 specification. Feel free to add it to OpenPBR surface and I will make sure LookdevX uses it.
Since the Maya team noted that they need this field in order to derive the node name (with correct capitalization and word break) to show in the editor: