You'll hear different input depending on who you're asking, but I don't recommend long-term steeping with the caps off. I've found that leaving the caps off tends to result in muted/lessened flavors. Leaving the caps off for a short period of time can get rid of the perfumey smell, but (for example) my 'Bacco B by Bombies sat with its cap off for about 2 months (accidental), and now it tastes like nothing. Like literally, there's hardly any flavor there, and previously it was a bold, punch-you-in-the-face kind of
juice.