My workaround for the problem, while not perfect, allows me to open 2 or 3 charts. I've created two separate windows accounts on all my exam room laptops.
The most common time i need multiple charts open is if i have a long chart that will take me a while to complete i want to save it till i get a break yet keep going. I "switch user" under windows and then open ac in the other user account. it takes a minute or two to do this, but it is better tyhan nothing. Just be careful not to "log out" of an account or shut down but "switch users" in windows. AC allows a user to log in from multiple computers simultaneously. just be sure you dont edit the same patient on multiple computers.