There is a hex edit which you can do to make it scroll fast without using the platform sprite:
[x2C9BC] Change to A9 08 EA and the background will start scrolling fast with generator F4 without having to touch platform C1.
If you don't actually want that, then you could use one of the sprites included in StarsW.zip, which lets you do left and right background scroll.
Look in andy_k_250's profile.