It would be awesome to allow opening multiple files in different windows to allow having side by side views of your code and similar functionality.

WWeeeeeell, actually, if you open up two instances you can actually browse side by side. However I haven't checked how editing code would be saved through each instance nor have I tried with any licences.

You'll get a message that the project is already open in another instance of the editor. I don't think it's trivial to implement.

The doable workaround is to use the collaborative development option described here:

Quote:One application has only one window so can be used only on one monitor.
But you can open the application multiple times, however - if you intend to work on the same project you need to:
Have 1 folder for Projects (with your project inside).
Then copy that folder to some other place in your disk, so you have 2 Projects folders.
Run 2 instances of the Editor.
Point each to a different Projects folder.
Start the Server app, and connect 2 Editors to it.
Now you can edit the same project with 2 Editors.
It's possible that one of the editors will ask for a new license key.