It doesn't seem like you are making big enough moves. Normally, I watch the 4 pin fall. When it falls late its an indication that my line is drying up. I'll go ahead and make a 2-1 move, 2 boards left with my feet, 1 board left with my target. This lets me keep the same breakpoint.
Some things to watch though is where other people are playing the lane. If they are playing inside your line, you may move right into the area they have already dried up.
I would recommend making larger initial adjustments in the 2d game. Your small adjustments are resulting in splits anyhow, moving too much should at least leave a makeable spare like the rail or a 2-4-5.
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~~~SrK - Have balls, will travel