Ignoring UI Enhancement and its side effects

Recently I came across a scenario where I used a feature in SAP CRM and then it had a strange side effect.

• When you choose to ignore the UI Enhancements , then you need to set the SU3 Parameter WCF_IGNORE_ENHANCEMENT = ‘A’. 
• Then if you try to personalize the Overview page and try to add few the assignment box to the Overview Page, it doesn’t happen. This is a strange behavior and I removed the UI Parameter and then I was able to personalize the overview page.

Now if you are in a Customer system and would like to check the standard UI screens , then it becomes very difficult if you want to personalize the screens.