Neither "Transfer Maps" nor turtle's "Texture baking" seem to have options for current pipelines (with more info channels than baseColor and normal). Arnold is even more limited for that.
The need to bake final light outside of game engines has become less common, while we always need maps like roughness and metallic.
Channel mixing should be handled too. Often each project need a peculiar selection of info channels packed together, like a RGBA texture with metallic, emissiveMultiplier, roughness, teamKeyColor. Maybe a rerouter node/interface.
Better if the tool could handle more shaders as input, specially Standard Surface.
Even better if the tool could be paired with (or handle itself) atlas generation.