Ability to have Non-parameter Textures / sample a texture more than once?

So I'm working on a shader at the moment where I want to use each channel of an RGBA texture as a mask, and have each channel/mask panning at different speeds. Right now i'm unable to do this properly as I have to keep adding in seperate slots and pan each of those individually. 

Would it be more efficient if there was a way to sample a texture more than once, maybe a non-texture parameter node or something?