You always get that message. You likely did not use an allowance. You can check your guest allowances under your Benefits Summary. The very last entry. It always says Developer although I believe it's one bucket and applies to your account regardless of the type of points used. The 1st number 2 is the number remaining.
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I think overall the programming around this has improved. If you add another reservation it's linking them -- even if it's another owner -- if I change the owner name it might tell me there is a relationship to another reservation (might - I haven't played enough, seems like I saw a message like that). And as always, keep an eye on it. But I do think it's gotten a little better. A though thing to program, IMO. (And the verbiage on the initial booking could certainly be more clear (as in be accurate), I bet they get alot of calls on this).