  In 2002, D. Fon-Der-Flaass constructed a prolific family of strongly regular
graphs. In this paper, we prove that for infinitely many natural numbers $n$,
this family contains $n^{\Omega(n^{2/3})}$ strongly regular $n$-vertex graphs
$X$ with the same parameters, which satisfy the following condition: an
isomorphism between $X$ and any other graph can be verified by the
$4$-dimensional Weisfeiler-Leman algorithm.
