For the email notifications, we are in the middle step where the UI is there, but it is not yet activated. For a variety of reasons this will take some time before it is enabled, sorry about that.
The example on GitHub uses a different method for handling multiple sensor. The BSEC Arduino library is a C++ wrapper over the BSEC C library. Since the C++ language is object-oriented, it instantiates 2 full instances of BSEC, in addition to using 2 save states.
This method uses more RAM than reusing the same BSEC library instance with multiple sensors, but does save some CPU cycles by avoiding the constant swapping of bytes in and out of BSEC internal buffers. It also does not work in C, which has wider compatibility than C++.
*PS: The Arduino programming language is C++, so it works on AVR targets, but is not portable to other targets without an available C++ compiler.