If you're going to go the D23 route for $500, remember you get a free membership with a
Disney+ subscription right now. And, from most recent reports, yes, that discount will available immediately. I don't know if you're an existing DVC member, but if you're not, you can also get $500 from using a referral - can find someone on the referral thread in this forum if you want. But, it is one or the other on those two discounts, so you can't combine them.
Delayed closing - spread out your payments on your contract as long as they will let you (60 days). If incentives improve anytime during that period, they will likely let you reprice it with the new incentives. Although they could legally hold you to the existing incentives after the 10-day rescission period, there are no reports of that happening - my own contract was re-priced in August after my 10-day rescission period but prior to closing.
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