No - my query is solely related to the question of how finger scans are associated, and whether they are done anew when a band uses a new ticket in replacement for an older, fully-consumed ticket.
The ticket scans are associated with individual ticket media. The first time you enter a park utilizing a particular ticket or pass, the finger scan is associated with that particular ticket or pass. Then the following times you enter a park using that ticket or pass, the finger scan is verified against the record of your original finger scan for that particular ticket or pass. As I understand it, once a ticket or pass expires, the finger scan associated with it is deleted.
The finger scans are not associated with MagicBands directly. They're associated with ticket media that themselves are associated to an individual's MDE account. if you didn't have a ticket or pass in your MDE account, then there would be no finger scan of yours saved in your MDE account, or associated in any way with your MagicBand. Of course, you also wouldn't be able to enter a theme park, either.
But none of that means Disney would not necessarily be able to determine that a MagicBand was being used with two different tickets with two different finger scans. A lot goes on in the background. There are instances where Disney references a group of tickets purchased together with a group of finger scans associated with those tickets.
For example, if a family of four that is linked together in MDE buys four tickets and enters the park with four finger scans, that same family can subsequently enter a park using the same four tickets and the same four finger scans, but each person using another family member's ticket. In other words, meaning on that second entrance, all four tickets and finger scans would be mixed up. Disney's computer system can catch that, and as long as one of the tickets and one of the finger scans from the original park entry is recognized, that person is allowed into the park by the system. So all four of those family members individually would be allowed in. The system does that so that harried parents won't be barred with their children from park entry just because they accidentally give the wrong child the wrong ticket or MagicBand. That's also why Disney allows parents to use their adult finger scan if their child's finger won't work the scanner.
So, pretty much, attempting to flout the system in anyway opens up a whole can of worms regarding how Disney cross-references for use-control purposes finger scans, ticket media, and linked MDE accounts. There's a lot more going on in the background than simply a single ticket or pass indirectly associated with a single MagicBand.
However, you have to be aware that Disney's terms of use state that MagicBands are just as nontransferable as ticket media. Disney may not crack down on the practice of sharing MagicBands when people are simply sharing FastPass reservations once they are already in a park, or as stated above allow finger scans and ticket media to be mixed and matched when a linked family is on vacation at the same time (the latter equating to allowing in limited circumstances the mixing and matching of MagicBands since that's how most people enter the parks.) But anything beyond this and you're running a risk of ticket media confiscation and potential penalties for the actual MB owner as well.
The specific reason MagicBands are nontransferable is so that people don't allow other people to enter the parks with them. So it feels to me like this detour that this thread has taken is essentially a discussion of how to bypass Disney's terms of use for MBs and ticket media, or in other words, "How do I break the rules and get away with it?"
FWIW, this is exactly why
Disneyland cast members take your picture when you enter the Anaheim parks for the first time on a multi-day ticket or an annual pass. That's rumored to eventually happen for passholders at Walt Disney World.
