I'm not familiar with your graphics programs, but an alpha channel won't make anything anymore 'low-poly'. The game will still process the vertices and polygons as if they were there, and it will still process them as if they were textured. In fact an alpha channel will worsen game performance, not improve it, as the game will attempt to interpret what colour to make each pixel on the alpha'd polygons from the surroundings, rather than simply draw it from texture.
|