SoCal Crescent hits some optional 6-8k' summit singletracks en route from Hemet to Palm Springs, but also includes the Palm Canyon Epic (or easier variations of it). I rode it for four days a year or two ago and had a blast. No bikepacking route in SoCal will include as much choice ST as this route, but you might be a tad early for some of the goods.
what is this SoCal Crescent route you speak of? I've never heard of that name before.
mike