Circular Brennan's conjecture

Let $f\colon\mathbb{D}\to\Omega$ be a bounded conformal map from the unit disk, and define the universal integral means spectrum by

$$B(t)=\sup_f\beta_f(t),$$

where $\beta_f(t)$ is the integral means spectrum of $f$. Circular Brennan's conjecture. The spectrum satisfies

$$B(t)=1,\qquad |t|=2.$$

This strengthens the known identity $B(2)=1$ by predicting the same value on the entire circle $|t|=2$, including Brennan's conjectural value at $t=-2$. The source gives no resolution status.