Distribution-constrained maximum stopping of maximum type

We consider the distribution-constrained optimal stopping problem $\sup_{τ\sim μ} \mathbb E[B^*_τ]$, where $μ$ is a probability distribution on $\mathbb R_+$, and $(B^*_t)$ denotes the running maximum of a standard Brownian motion. This problem was introduced in Beiglbock et al. (PTRF, 2018), where