I'd disagree that splitting the bill is annoying to the waitstaff. When I was in college 20 years ago, I waited tables, and I seriously enjoyed any time someone split the bill since it usually resulted in a larger tip. Plus, our software, even then, was set up so that when you entered the food, you entered it by seat, which takes all of a second to establish. You can then split seat one and seat two seamlessly. It's even better when you don't use the computer to split it, though, and the people decide to both pay in x amount of cash because when they both have cash in hand and are deciding what an "even" split would be, they both want to demonstrate to the other that they like to tip well. Or, if one of them is anti-tipping, the other usually manages to successfully browbeat them into doing it.
From my former waitstaff perspective: Please, by all means, split the bill. It's not annoying, it's gravy.
Note: If you do split the bill, though, make sure to stipulate in advance who intends to pay for any and all shared appetizers or desserts.