I cut mine a little each trip until it worked. Only have to cut one, as the other is not between wheels. I didn't go to the first hole. Didn't need to go that far.
I used a 12" miter saw to do the job. Worked like a charm. I also chamfered the edges that might contact the tire so that there was nothing sharp.
Works very well and didn't notice any change in small adjustments. Think about it, the height on one wheel is cut in half. So, the one I cut has a minimum adjustment of about 3/4" and you cut that in half. If I need small adjustments, I just use one leveler and I use the one that isn't cut.