v226 DevKit will expose the Elevator’s Activate() function to Blueprint 
It’ll also do two other neat things: Expose the TryMultiUse() function to Blueprint so that it can be called directly by any Blueprints (thus you wouldn’t even really need that Elevator Activate function exposed directly), and also in PIE it will draw the activation ID’s of all the activation options so that you can know what the numbers are to pass into the TryMultiUse() function – this will allow you to trigger any kind of use/activation through Blueprint directly.