to keep them lined up i drew 3 triangles in marker on the top rim of the kiln walls at about thirds of the way around the kiln. very seldom do i need to put posts outside these marks by more than an inch or two. i put them at the edge of the shelf so i can use every inch of space. after a year or so i re-draw the marks because they do fade over time.
I do this with a "permanent" marker pen but the marks burn off in every firing, (I expected them to) what are you using as a marker?
If I used an oxide based stain, would that be bad for the kiln (bricks)?