I reread the topic and wanted to jump in now:
1. You don't have to ask this if you're in any road race in the states that matters that much. Your team will hand you a bike, and you will ride said bike.
2. Events with that kind of elevation or distance aren't going to be USAC races for our level, most likely. They're probably fondos. Maybe Haute Route. But, it isn't a USAC race. Given that, if we're talking fondos with timed segments.......sure, it'll save some ticks on the clock. But I'd bet you'd save more time buying a smart trainer and a coach and just making more power and weighing less yourself. Assuming you're not riding a cement mixer right now.
3. US road racing is crits. Road races are few and far between. They're often pretty flat. Your bike weight and maybe even aero won't hardly matter for squat unless your only hope is a breakaway artist. Even then, Cat 4/5 chases every freaking thing down. Cat 3 and faster? You'd have to be strong AF to get away.
I'd say an honest budget for someone who hasn't raced road yet is to find a $1500 used carbon bike with 11spd Ultegra on it. New cables, new chain, new cassette. Go race. Learn. Grow. Then buy some wheels. Then, if you must.........upgrade the frameset and move over the components.
Don't go buy a $8000 frameset for your first races. If you're rich, sure. Do it. Enjoy. If you're not rich, start with something you won't mind scratching up some and possibly laying down in a corner.