I'll have to agree with the other commentators and say that I would love to see you expand upon the lore and narrative resources. The more customizable world-building the better!
In addition to this, it would be great to see you add to the co-op/gm-lead gameplay a little, maybe by adding mechanics for things like group combat or interactions between PCs. As much as I love playing Elegy on my own, I've been (I'll admit) vaguely annoying about getting a few of my friends into it as well, lol.