I have a list-user field that will include at least 2 users (but possibly more down the road as the number of users increase). I need to be able to default this field to specific users. Is this possible?
It does not appear you can set default users in a list user field however, you should be able to run a form rule when another field changes. When the form rule criteria is true, it could change your list user field to the selected users.
Yes it is possible with script. Instead of clicking on the native buttons to add a new record you will have to create your own custom button and arrange for it to run a short script. The script will use API_AddRecord to create a new record via an AJAX request and then redirect the the normal Edit Record page and it will appear as if you User List field has a default value. You can specify the multiple values by simply giving the User List a semicolon delimited list of email addys as I have done in the script below..