My sister has a couple of SWUs expiring on 31Mar that she says I can use. If I book a RT for April or May SAN-DFW/CLT-FRA ,for example, and just the SAN-DFW/CLT segments are confirmable right now at booking. It will still be an active waitlist for the intl segments post 31Mar using those same SWUs, correct? Or will they require me to use of my own 2026-27 SWUs if it ends up clearing closer to departure?