Does one account support simultaneous use on multiple devices?
Not supported. One account can only be logged in and used on one device at a time.
If you are already logged in on one device and attempt to log in on a second device, the following message will appear:

If you click 'OK,' you will continue to log in, and the account currently in use on the first device will be forcibly logged out. Click 'Save As' or 'Save' to save the current file locally; clicking 'OK' will directly close the software.
