Okay--will give it a shot . . . .
We have a large family that likes to travel together. My party of nine that visited last month included my wife and I, my in-laws, and five kids. We booked a bounce back for free dining next year. In order to get as many rooms as possible, each adult booked a room on the bounceback--so four rooms were able to be booked. This is all fair and legal with BB rules. But, each one of those adults has to be the primary reservation holder on a respective room with a separate reservation for each. (As a frequent traveler with up to 18 folks at a time, this is always troubling since I am the one that organizes, reserves everything for everyone--would much rather there be one reservation number, one pot of
Disney dining plan allotments, etc, but I digress). The reason for getting the four rooms instead of the two is so we can expand our trip to include other family members for next year. There is always such worry IF free dining will happen and when it does, there is always such a scramble---we were glad to be able to book the BB and include other members of our family.
Here is the rub. My wife and I will sleep in the same room even though we are "technically" in different rooms. The same will happen for my in-laws. We have managed this in the past with just using one of our bands to get in the room (and then allows one of us to have the other band to get into the room where our other kids are sleeping with in-laws). We all eat together, and use the dining plan credits very carefully, keeping receipts and keeping track. What would seem the easiest thing, in IMO, would be to have my FIL's band actually be worn by my wife's brother, and vice versa--that way, he can get into the room that he is sleeping in, be attached to the dining credits in said room, etc. My concern is that since my FIL has been to Disney many times, will his OLD fingerprint image data be tied to his NAME, and his ticket tied to his band. Does that make sense? (I know that this is dizzying). So, when my wife's brother (now going on day one with a ticket that is actually in my FIL's name) goes on day one to scan his NEW ticket for next year, would be get potentially stopped because in actuality, he is actually using a band that is tied to my FIL and his biometric data from year's past. OR, is the image taken on the scanner refreshed every time a new ticket is tied to it. By the above responses, I am getting both opinions!!?? So, we are not trying to cheat anyone, just trying to get people shuffled around a bit within the four rooms to sleep with their mate

PHEW!