I haven't been able to figure out RMC I-beans yet, but I have been able to get Topper Track using TheCodeMaster's tutorial. This tutorial does explain how to do the crossties, though I haven't been able to get them to work on my end, so if you figure it out let me know as well!
I would attach the download link here for the altpac settings, but since we can no longer do that you'll find the download link in the video description!