Yes, but you must be cognizant of your capacity. It is important that you are able to attend to all projects and contests you are responsible for with the highest level of diligence and service. If you take on more than you can handle it can have a negative impact on everyone involved. There are plenty of opportunities to copilot projects, so don't feel rushed to sign up for everything (just like you wouldn't sign up for every contest).
Also, keep in mind that your performance is tracked in your copilot profile. So, if you take on too much and your stats degrade it will be noticed by customers.