Creating a WebHelp project from an existing WinHelp or HTML Help project would be a straightforward migration. All map ID and Topic ID information would convert and be assigned to the WebHelp topics.
Let's assume that the client would use the RH_ShowHelp function to call help topics; the process of migrating the Topic ID and Map numbers to a WebHelp project should be rather direct, since the developer "simply drops the provided source code into a development project to quickly connect to the Help system." The RoboHelp help file also provides good examples on the code required to enable the functionality.
Developers may not be well informed about the new API, and they may have initial reluctance to migrate to an API that hasn't been fully tested in "their" environment. Those fears should be alleviated once this new API is fully understood.
Help authors must be prepared to demonstrate how the API works and have sufficient knowledge to communicate this information to developers. Many developers may be familiar with the prior method of calling the individual HTML files from the application, rather than using map numbers with the new API.