Time and Labor Auto Enrollment Questions

Hi everyone- I'm refining my setup document for the delivered Time and Labor Auto Enrollment and am about 90% there, but have a couple of questions.

1 - On the Installation table, it mentions Retro Limit.  Our business has decided that our retro limit will be 6 months.  I'm taking this to mean that if they do any retro-job change action up to 6 months in the past, the time and labor job will trigger and change the workgroup if/when appropriate.  This is my question - if we go live with this new functionality on 7/1, do I need to make it effective 6 months prior to that so the system will process those retro-actions?

2 - Also on the Installation table, there is Enrollment Inactivation setup - and we've chosen 14 days.  Do I have to do anything else?  I'm confused because I see in Peoplebooks each Workgroup has an Auto Enrollment Option tab, do I have to update this for each workgroup if I've already entered the information on the Installation page?