single axis Projectile Acceleration

While we currently have proj:SetAcceleration(accel), can this be abused to change the acceleration of just a single axis after its already in flight? The Wiki doesn't appear to show anything one way or the other.

Quick example:

local x = 0
local y = -1
local z = 0

That would probably be Get/SetVelocity.
Acceleration is used for the projectile to reach it's max speed

You can adjust this with Projectile:SetBallisticAcceleration(y). Gravity is -4.9 by default.
The documentation is a bit outdated, but you can also do SetBallisticAcceleration(x, y, z) for acceleration in any direction; I just tested it. Make sure your projectile's MaxSpeed is high enough for it to accelerate how you want it to.