Once an idea submission form is created you are only able to assign a submission to one person at a time. The ability to assign to multiple (IE two products are touched, two person team, collaboration, etc..) users would be much easier than having to use the work around of using the 'watcher' option.
Thank you for your idea. One work around here would be to add a custom users field for secondary assignees. The Aha! record relationships section of this article will provide more details on setting this up.
At this time, given the option above and other priorities we are unlikely to implement this idea. We hope you can understand.
This would be very helpful!