We've taken a quick internal review of the documents to be sure we're on the same page as you. Below, please see a response from one of our staff who handles the guides:
"That's correct that the current Android user guide does not include Connection Reuse.
The user guide gets updated for every dot release (2.0, 2.1, 2.2), but unfortunately not for every patch(2.0.1, 2.0.2).
However, to fill the gap, we publish help and Release notes for every patch release. We are working on updating the user guide for 2.1.0. In the meantime, the description on Connection Reuse can be found in help in Bria under Settings > Help.
As for PDF security, it is our policy to secure our official documentation. We allow users to copy and print PDF documents for their use. Let us know what you want to add in the user guide; we will make sure it covers everything our users need."
So if you have recommendations or additions, please do let us know. We value your feedback!