Even if they have posted that date to be ultra conservative it...

Even if they have posted that date to be ultra conservative it is still the date.
If people follow your advice in your first post they will be terribly let down.

T+3 is a payment settlment system, that's all.
Somewhere in the time frame is time for the registry to recieve and input its own information. The eligibility data will come from the registry not the brokers settlement data.