Here are my test results from training Carpentry 50-100, recycling everything that I crafted. I did it simultaneously on 3 characters, and the average boards consumption was 153.000 and the total time spent was 23 hours 12 minutes. I crafted the items that I assume corresponds with the ones Luthius has based his skill gain chart on, at least the resources per attempt are the same. However, his estimated resource use from 50-100 is 220.000, my tests used 67.000 less on average. I'm not sure if his figures are with or without recycling.
Details in the attached picture:
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Details in the attached picture:
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