Ambiguous URLs and their effect on Exchange 2010 to Exchange 2013 Migrations

Brian, thanks for your reply. I wasn't clear when I referred to checking the box "on fast networks, connect using HTTP..." many times - I meant that I check the box each time when setting up new profiles for users, which I've done many times. Once checked, the setting does stick. I've been able to incorporate that setting into Outlook 2013 using the office customization tool, but it's not available in the Outlook 2010 office customization tool. I would love to do just what I think you described; issue a setting server side through autodiscover which would implement the "on fast networks...use http" setting -- but in Exchange 2013 for all Outlook versions. If possible how do we do that?