Why:
You may lose the customer's embed qualities and formats if you don't do this
The information is located in the DAM Center → System tools → ConfigManager → Config Parameters and take a snip of the result - paste it into a document (just in case...)
Before updating, if the customer has a MM, and has embed, please note down the embed qualities and formats in MM's "video embed qualities" list. These may be reset upon DC update to 4.7.0 (IHP experienced this - This isn't necessarily true - if you find out it isn't, then delete this line). After updating, revert the qualities back. This is done solely from the MM's config manager.