Faudree–Rousseau–Sheehan's strongly regular graph conjecture

A strongly regular graph $srg(\nu,k,\lambda,\mu)$ is a graph of order $\nu$ that is $k$-regular, with every adjacent pair having $\lambda$ common neighbors and every nonadjacent pair having $\mu$ common neighbors. Define

$$s=k-\lambda-1,\qquad t=k-\mu.$$

Faudree–Rousseau–Sheehan's conjecture. There exists a constant $c\ge2$ such that for every strongly regular graph $srg(\nu,k,\lambda,\mu)$,

$$2(s+t)-\nu\le c.$$

The paper says this conjecture is closely related to the linear upper-bound conjecture for book Ramsey numbers and places it in the context of strongly regular graphs, which provide lower bounds for related Ramsey numbers. No resolution is given in the supplied source.