So you might have noticed if you try to start another instance of after effects nothing happens. There is a little trick to start more copies.
1. Start AE, then start your windows task manager. Go to the processes tab. You should see AfterFX.exe Right click on that process and at the top of the popup list say "open file location"
2. This will open an explorer window with afterFX.exe selected. Right click on it and select "create shortcut"
3. Right click on the shortcut that is created and go to "properties" at the bottom.
4. In the target field at the very end put a space and then -m
Make sure you put a space or it will give an error.
That's it it should let you start multiple copies of AE now!