multiple .ipr files on same project cannot open multiple frames

I have a project with multiple .ipr files pointing to the same .iml

For ex:

 - MyProj.ipr

 - MyProj2.ipr

 - both point to MyProj.iml

I would have MyProj.ipr and MyProj2.ipr both open in separate frames; this is esp useful on a multi monitor setup when comparing db queries and result sets and other things.

As of IntelliJ 2016 2.2, IntelliJ will not let me open MyProj2.ipr if MyProj.ipr is open.

What has changed?

Is there a way to disable this "block" via properties so that I can again have MyProj.ipr and MyProj2.ipr open simultaneously?

I have been an IntelliJ user since version 3.x and I'm very familiar with settings and I'm happy to dig about in there.

Thanks