Are there complex projective elliptic threefolds $f: X \to S$ with infinitely many rational sections satisfying the following properties?
- $S$ is a smooth surface of Picard rank $1$.
- $X$ is smooth with $q(X) = 0$. (Bonus: $\kappa(X) \ge 0$.)
- The discriminant locus of $f$ in $S$ is smooth.
If we drop any of the conditions above, there are examples of such elliptic threefolds.