Up-elbow bound conjecture for bumpless pipe dreams

Let $\omega$ be a permutation, and let $P\in\operatorname{Pipes}(\omega)$. If $P$ is non-reduced, replace the redundant crossings with bump tiles. Up-elbow bound conjecture. Pipe $i$ has at most $r_{\omega^{-1}(i)}-c_{\omega^{-1}(i)}$ up-elbows, including the up-elbow portions of any bump tiles. This generalizes the proved bound for vexillary permutations to arbitrary permutations; the source gives no resolution of the general case.