This. This is something that has to be finished. There's not enough FELT (and I could add some other circle names, like ZYTOKINE or hatsunetsumiko's, but it'd be a too long list) on Osu. There's not enough Touhou in general, but I think FELT is one of these circles that can easily be listened to by non-Touhou fans, too, due to the quality of their songs, like "Lost in the Abyss", or "Lost My Way", or the slightly older "Once Upon a Love".
I wish I was able to map songs (I tried and failed hard several times) so I could help, but I can't, so I'll just cheer up any effort to have all of the songs mapped, one day!