Why would you not want to use send keys if nothing else works for you? There seems to be a common theme of users not wanting to use Surface Automation techniques - but if they are used correctly and training best practices are followed they are as robust and reliable as any other interface.
There is a new send keys guide here just to reiterate some of the best practice lessons: https://portal.blueprism.com/system/files/2018-01/Guide%20to%20Send%20Keys%20and%20Send%20Key%20Events.pdf