I’ve always wanted to add system.opcua.readAttribute and system.opcua.writeAttribute, but even with its status as something of a wishlist item of mine, it hasn’t been able to claw its way into this world.
I think in part because the reality of the implementation is it will be ugly, like the BACnet read/write raw scripting functions, where Milo types have to be injected into the system.opcua namespace so they can be referenced by scripts using these functions, particularly writeAttribute.