Tracer should build up into a sub 30lb bike easily I’d have thought (with careful component choice at least), it’d be my choice anyway. Well, it’d be my choice full stop really, would absolutely love one!
If it’s going to be more of an XC bike though, you could look at the Maverick Durance (or an ML7.5) as they’re cheap right now. Or of course the new Turner 5 spot. Had a look at an Ibis Mojo yesterday, very nice indeed, though I don’t think I’m trusting enough of carbon yet to deal with the kind of abuse a frame of that travel can get you into, if you get me. On an XC race bike, carbon frame all the way, but I’d still stick with ally for a near 6″ travel bike personally.