Imo, multiplayer in ksp should be more of a co-op experience, I wouldn't want to play multiplayer with more than one other person anyway, at max 3. Rather than the other player flying multiple ships you cooperatively work on the same ship (occasionally controlling two ships for docking etc), then you just sync time warp with the other player. I'd also like to see multiplayer in the VAB, it would be cool if your friend builds the lower stage while you're building the upper stage. KMP does have an interesting solution to time warp, but it does seem a little convoluted. I can't imagine squad going that route if they ever did implement multiplayer.