I still don't know how I could fix the tearing effect on the character when the room scrolls but it's fine for now. If anyone knows please tell me.
I alone know.
I got sick of the strobe effect when the character walks in a scrolling room.
So I use this in Global script repeatedly_execute
//THIS IS OLD CODE 4 OLD SKOOL PEEPS
And just watch how smoothly the character walks.
I'm convinced that this is a step closer to make dual sprite animations smooth too.
Now you know it too.