Solution for animating material to preserve DrawCall batching

I use a parent empty GameObject with a single *.anim to pass information to children to manipulate vFX polys for explosions, flashes, spells etc. [deployment to mobile, I am to avoid emitters]

By doing so I gain a great deal of motion graph control for ease/timing, scale +better pivot point control. However keyframes attached to the material convert each to an (instance) at run-time, obviously ruining any optimization I was hoping to gain

So I am trying to key alpha offset to create sophisticated dissolves (rather than fade i.e. alpha gain) but can't exactly do this on the vertex level since that would function multiplicitively.

Is there a lerp trick I could perhaps perform between a second set of UV coords (using a single pixel on the texture atlas) that could allow me to key a change in alpha using an additive function without ruining the material for batching?

Would the very act of altering a planes alpha break any hope of batching in the first place?