First, please bear in mind that these forums are a place to chat with other customers, not with Omni’s support team. I’ve just updated the welcome message to make that clearer:
https://discourse-test.omnigroup.com/t/welcome-to-our-forums/21938/4?u=kcase
With that out of the way…
You can get the behavior you’re looking for by setting the ShouldOpenLinksInNewWindows
hidden preference. The simplest way to do that is to use this URL:
omnifocus:///change-preference?ShouldOpenLinksInNewWindows=true
Once you’ve done that, clicking on a link which opens in OmniFocus will open it in a new tab or window (based on your “Prefer tabs when opening documents” setting in the Dock section of System Preferences).
If you wish to return to the default behavior (opening links in the same window), use this URL to reset that preference:
omnifocus:///change-preference?ShouldOpenLinksInNewWindows=
Hope this helps!