According to the
BOSE AM-10 owners manual, it does allow a connection directly to the LFE output on the receiver as well as to the five speaker outputs.
So, he can connect one bass toaster completly, with all the speakers connected, and the other bass toaster via only the LFE connection.
Of course, if he doesn't have the required propriatary Bose cable for the second toaster, he may well be scrooged.