General global maximum conjecture for the rank-two likelihood model

Let $n\ge2$ and let $s,t$ satisfy $0<t<s$. For positive $u$ and positive integer block dimensions, write $(u)_{l_1\times l_2}$ for the $l_1\times l_2$ matrix all of whose entries equal $u$. Let $L(P)$ be the likelihood function defined in the source by equation (newLP). General likelihood conjecture. The matrix

$$P=\frac{1}{ns+(n-1)nt}\begin{pmatrix}\left(\frac{s-t}{\lceil n/2\rceil}+t\right)_{\lceil n/2\rceil\times\lceil n/2\rceil}&(t)_{\lceil n/2\rceil\times\lfloor n/2\rfloor}\\(t)_{\lfloor n/2\rfloor\times\lceil n/2\rceil}&\left(\frac{s-t}{\lfloor n/2\rfloor}+t\right)_{\lfloor n/2\rfloor\times\lfloor n/2\rfloor}\end{pmatrix}$$

is a global maximum for $L(P)$.

This is the paper's proposed extension from the four-by-four case to arbitrary $n$. The source does not reproduce the definition of $L(P)$ in the supplied context, and its discussion says that an efficient method for $n>4$ is lacking.