When I re-designed the boot menu, I created all the different elements I could think about. The intention, hopefully, for advanced menu was you could create menu’s like everything else and associate them to the “advanced” side. That said, I still don’t have a good understanding of how to implement a menu system that would link to the advanced system. The item is designed, but not flushed out. So for right now, the “Advanced” and “Advanced Login” are essentially simple placeholders for a feature I might get to think about and implement down the road. Mostly, these days, I’ve been more worried about working out bugs and minor things for 1.5 while working toward getting 1.6 to a more suitable testing state.
Mind you (et. al) that I just started a new job and have much less time than in the past to actually work on FOG. This doesn’t mean I won’t work on it, simply that I’m very busy during the working week and by the time I get home it’s nearly time for bed already 
Hopefully this helps you understand the ideology, even if it doesn’t work quite as I would have hoped (or as anybody might expect.)