All of the above is very interesting information, but it appears to apply only to standby/upgrade for domestic flights.

In another thread I asked whether checkin for a domestic flight connecting to an international flight prior (or even after) the 3-4 hour window opens for gate listing for a requested mileage upgrade that has not previously cleared.

Specifically, does the domestic checkin with issuance of the BP for both legs automatically register as checkin time for the international flight? Can the airport ticket agent at the origination city put in the request for the mileage upgrade on the international flight?

How does a Pall List work for International?