I think it's fine as a prn if you don't drink it all the time. Once it's a habit it can suck. I get caffeine headaches if I quit cold turkey.

Its also okay if you don't experience acid reflux. Stress can contribute to that which will make your stomach upset which isn't a good experience. If you have a sensitivity it will make you anxious. Just listen to your gut and don't drink it a lot.

I work in fast food and people are given 15+ hr shifts if they need to cover hours for someone else. You can request two 30 minute breaks after 8 hours.