Bradley-Terry and Elo scores are equivalent mathematical models! The fundamental presumption is the same Thurstone model - that an individual's skill in a particular game is a normally distributed random variable around their fundamental skill.
We did experiment with a Bradley-Terry loss function (https://hackmd.io/eOwlF7O_Q1K4hj7WZcYFiw), but we found that even better was to calculate Elo scores, do cross-query bias adjustment, and then MSE loss to predict the Elo score itself.