The 1.25 speedup conjecture for unicasts and broadcasts

Consider a $K\times N$ switch with traffic patterns consisting only of unicasts and broadcasts. The 1.25 speedup conjecture. The minimum speedup required to achieve $100\%$ throughput is exactly $1.25$. The paper presents this as a conjectural extension of the $2\times N$ enhanced-conflict-graph approach, motivated by simulations; whether the bound is exact for general $K$ and $N$ remains open.