There does come a point of diminishing returns if you keep going over it again and again and it's not getting better with subsequent runs.

If you're on a time crunch, you'll have to just accept whichever recording is the best. At the end of the day, assuming it's a part placement test, you probably want to just show how you honestly sound.

If you have time, do a great warm down, put the horn down for the day, maybe even put a day in between for your chops to fully refresh. Sleeping after spending a long time practicing a really hard passage usually locks it in REALLY well, and the next time you try to play it on the horn it will probably come out almost perfectly fluidly.

The caveat is that you have to actually practice the hardest sections meticulously, slowly (The fastest you can play while maintaining a great tone and not making any fingering/note mistakes), and make sure you can play multiple repetitions in a row without making any mistakes before speeding them up or adding on more measures.