Popout windows feature?

[RMcNeely]

Doesn't look like discussions are enabled here so I hope you don't mind an open issue.

I am just wondering if Tangram has a method of opening new windows? My use case is a Slack huddle which I would like to pop out into its own pane and move around. Currently if I hit the button in Slack Tangram recognizes the intent to launch a new window and reports its intent and launches an XDG portal. It appears to be trying to find something with x-scheme-handler/about. I am getting this from what comes up if I search for an app. Not sure if there's a way to handle a specific intent scheme in a new WebKit window?