That's a good thought except that there is no way to validate that the coordinates are the correct ones for that location. You could still put a value in there but it would not slew to the correct location if it is not right. If the value is set correctly the first time (assuming you are not traveling too far from the initial location) then it should work okay. The user needs to be knowledgeable enough to understand the importance of the location data and keep it in mind when setting up their mount. One of the issues we have as a manufacturer is that we have to assume a certain level of knowledge and skill for the customer when creating documentation. For instance, we need to assume that the user knows how to use Windows and can install and configure programs on their Windows device.
I think your suggestion is good, but I also think that there is nothing wrong with making mistakes. It's how we learn things. I always say that we don't learn anything by being successful, it's only when we fail that we learn. So I don't think it is bad to have the mount slew off in a wrong direction per se, as long as the user can figure out what is wrong. I would suggest that we put a caution in the manual that says that if the wrong coordinates or no coordinates are put in the setup preferences then the mount will point in the wrong direction. We don't explicitly state that, but again, the assumption is that the user will understand that implicitly if they understand the purpose of those values, along with the time being accurate.
Let me know what you think of that approach.