There is a saying “Act in your new role before you get it” and I do agree that this is a good way to move forward and the firm loves it. You are paid for instance as consultant and already deliver as project manager. Unfortunately the promotion timelines are still fixed so you are taking on more for less for quite some time. I basically ran projects 2,5 years before the official designation to project leader. You get really good in your role before the designation and rock afterwards as well but be honest with yourself and figure out whether this is really worthwhile.
For many insecure overachievers this is exactly the way to go and you might enjoy it as well. Real fast track promotions happen not through your work alone so make sure you got all pieces in place to rock your consulting career.