But M&M is not a last minute booking FFP, you always face the 48 hour deadline.

With the American FFPs, I found that they do not use -24h but time-of-day-24h for issuing award. For me that is time-in-China-24h >= Central Time ... which is some 11 hours for UA MP.
AA additionally allows for a significant grace. I was once able to get a partner award (term now used properly) on CX at -120 minutes out to get my assistant back.
I heard that some LLC FFPs do allow actual walk up redemptions but am unsure if that's a rumour.