I somewhat stumbled across this feature while testing out the Dev build and I've quite enjoyed it. I have noticed though that the sites that have been installed as apps still seem to share cookies with the rest of the browser though. It would be nice if when a site is installed as an app it becomes containerized.
@geek2point0 thanks for the feedback. I'm glad you found that feature. I'm the dev lead on it, so I appreciate any suggestions or bugs you come across. Believe it or not, it's a super complex space and we are actively coding for it, but it's going to be one of those features that evolves over time as we get feedback and learn.
We actually designed it to share cookies because it's just a new instance of the browser itself without all the UI. If you install a site, for example, you can still browse to the URL in Edge while running the site as an app. If we didn't share cookies, it would mean that your experience would vary widely from the browser to the app.
The most interesting part about this for me is that developers who write code for this feature and end-users who benefit from that code are likely to have very different expectations about what "should" happen in different scenarios.
I'm continuing to think through these scenarios to try to make this awesome for everyone.
@johnjansen thank you for the quick and informative reply! I can definitely see what you mean about the different expectations. To amend my initial suggestion, it would be nice to have the OPTION for the app to be isolated.