If you have a enhancement request, you can post it on the ideas site of Esri. There are several related to Collector:
http://ideas.arcgis.com/apex/ideaSearchResults?s=Collector&searchButton=search
If your request is not already listed you can add it. After creating the idea, post the link in this thread to gain more support for your idea. Esri is constantly looking at these ideas. And those that have a lot of votes may be included in a next release.
Kind regards, Xander