I thought on the 737 that this checks apply on each crew change. Looking at the FCOM again, I guess it really says "once per flight day".
Anyway, I'd check things when I arrive at the aircraft. Why not find out things are wrong at your base, where you can have them easily fixed or aircraft swapped? Kind of like departing your base with ignition on L (even if it is your odd-numbered sector) - it just doesn't make sense.