At the moment, the program is beta quality. Nonetheless, it might be useful to others, even at this stage. It is not necessarily ideal to use on a public computer terminal, or any place where security is paramount. Some security auditing has been performed, so I believe that it should be very hard, if not impossible, to crash the program once the screen is locked. (the main point of failure would be it failing to lock) Nothing is guaranteed, (there is no warranty) but to the best of my knowledge, it is now reasonably secure, provided that you are using current versions of libraries.
I don't know if it works with Xinerama, since I don't use multiple monitors. If anyone has any code/suggestions towards improving that feature, I am definitely interested.