Indeed it is. Standard compartment spacing often results in a stoker's head being too close to the captain, affecting vision and standing while pedaling. This spacing probably has had its origins in aerodynamics for racing. But most stokers could care less about racing and would prefer another few inches to enhance enjoyment of the ride...not that they don't love their captains. Even with a few more inches, there is still plenty of aerodynamic gain and so no need for a stoker to bother with drops.