One of the consequences of the well-known Motzkin-Taussky theorem (https://www.jstor.org/stable/1990825) is the following : if two complex matrices A, B $A, B$ generate a vector space of diagonablediagonalisable matrices, then A$A$ and B$B$ commutes and in particular are simultaneously diagonablediagonalisable.
Does the result hold for nilpotent matrices : Let A$A$ and B$B$ two (complex) matrices such that sA+tB$sA+tB$ are nilpotent for all $s,t\in \mathbb{C}$ are they simultaneously triangularisable ?