A couple of tips:
ONE: The 2nd and 3rd Family Pack purchasing options will not show up until the 11th and 21st device as the 1st Family Pack will have to get "filled" before you are presented with the option to purchase for the 11th device. But no issues as every device enrolled is enrolled into the fully functional trial first.
TWO: For Bulk management, in the Boomerang Web Management Dashboard which is available at: https://app.useboomerang.com/My. Here, under the hammer and screwdriver icon, we have an Export/Import feature. Export your configuration, save it to the desktop. Then Import and apply it to get your configuration. Also works on multiple child devices so a nice way to clone your configurations rather than doing them one-by-one.
What is the cost of Boomerang and How do I purchase?