Redmine

Hello,
Is there a way to list the number of issue assigned to a custom user ?
We are using the custom user to have 2 people reviewing our issues.
With the addition of the notify_custom_users plugin, that's perfect..
Except one thing, we don't know how many issues are already assigned to each custom user.
That would be great to have either a way to display a list of all custom_user with the number of open issues assigned ; or this number between brackets on the right of each name in the dropdown list.

Thanks