I posted this here Have Virtual Agent pop up when service portal is v... - ServiceNow Community for someone else wanting to do the same thing just based on my experience.

If you have it set to automatically popup when entering the portal, it will start an interaction/conversation automatically and why I went away from the OOB widget. If this is something you want, I understand but make sure to filter out some topics from reporting as you will have quite a few abandoned items as not everyone will do anything with it. For some reason OOB it would do that automatically when I enabled it but as soon as I cloned the widget it stopped.