Walter,

     This as of WFA3.0 can't be changed. I don't know why this was designed this way i.e. allowing only the Admin to modify the client preferences for executions page which is a local browser setting. I think all other non-admin users always see the default i.e. <=100 workflow executions unless you have modified this seting using an Admin login from the same browser session. After that it will show accordingly.