If anyone is interested I have uploaded A C# library for control of XpressNet compatible model rail command stations to GitHub at https://github.com/networkfusion/XpressNetSharp Documentation/Example app is a bit light at the moment but I hope to improve it over time. But if you are any more than an ameteur developer hopefully what I have written will make sense. It was designed from scratch to be as speedy as posible with an event driven architecture and is much more complete command wise than many of the other libraries available.
I also have a full program that is capable of talking to an eLink (wont work with the out of box example due to a boot sequence check packet). I did plan to release it this year but since moving to a house that needs a lot of renovating, I haven’t had the time to improve it to a state where I think it is ready. However if anyone wants a try, PM me and I may send you a link. I spent a extrordinary amount of time working on the communications aspect as such is much less prone to USB errors than RailMaster.