@pippideb Time in service counts regardless, so with 4 years enlisted service, you'll get paid as an O-1 with 4 years of service. (Using the 2022 pay chart, that's 4375/month base pay instead of 3477).
@catholicmagus I've always received a separate travel W-2, rather than my normal W-2 including the PPM payout.
But the overall point that the paid in '24 means that it is filed in '25 for '24 taxes is correct.