I think my suggestion would be only one modification per reservation within the 11 month window to the
original check in date. Any subsequent changes would be cancel and re-book. So if you book Jan 1 to Jan 7 you could only change the start date, to say the Jan 7-Jan 13, one time. If you make that change and then want to change to Jan 13 to Jan 20 you would have to cancel and re book like everyone else. Sure people can still walk a week, but that's better than some of the examples I've seen where people walk for months. Allowing the one modification also allow the person that books Thursday to Tuesday, then realized Friday to Wednesday works better, the option to change without losing their desired room. For anyone who has to change dates 5 times in the first week of booking you just need to plan better. And even though I have zero evidence to back it up, I bet if you looked at 100 random reservations that are modified significantly in the first weeks after booking, >90% would be walking versus legitimate date changes. I don't mean adding or losing one day. I mean shifting reservations a whole week.
I don't know if Disney could/would want to build that into their website so I would even suggest making that one change call-in only with Member Services. Allowing only member services to make that change could even leave it open where in extenuating circumstances a supervisor could even grant a second change in that time frame (military orders changing, school calendar shifting, etc). There wouldn't be many instances where people would legitimately need to change so many times so far out, so this would give MS the power to make a change if they deem it reasonable. Kind of how sometimes airlines refund or change non-refundable or non-changeable tickets.
I say this rule only applies to check in date because I think people who book 7 days should be able to add more nights to their reservation up to say, the 14 nights, that was purposed up thread. People booking longer stays aren't booking rooms with the intent to cancel them later, so I don't think they should be punished.
While walking isn't explicitly banned in the POS or
DVC rules, I don't know of any lodging company which wants customers to take rooms out of inventory with zero intention of staying in them. People doing this in the CRO side is the exact reason Disney is changing the 60 day onsite fastpass rule. People are taking rooms out of Disney's inventory and dumping it back on them with little time to then sell it. I'm active on several mile/points forums and hotel & airline companies have been know to ban customers who book too many flights/hotel rooms with zero intention of using them. Sure, people end up in the rooms after walkers con't their walk. But if two members are trying to grab the released days and member 1 gets the first day and member 2 gets the second day and so on they end up with mishmash of worthless days. If i was one of the members trying for those released days I'd rather get my whole stay or miss out completely and book a different room. Having the inventory removed by members who don't want it isn't prohibited, but it also isn't in the best interest of the whole membership. DVC is charged with doing what's in the best interest of the entire membership. While people can make arguments that it's not against the rules, I don't know how anyone can make the argument the entire membership is better off allowing walking.
Short of lessening the spread between the highly sought out, lower point rooms and the regular rooms (and jacking up AKL Concierge even higher) I don't know how else to get people to stop walking.