No worries about the graph. I am 61 and not an engineer, and I wrongly assumed with you being so young, that your background in engineering would require you to be fully adept at digital graphing. I thought it would be a simple task for you.
The "boil" effect is interesting. Never heard of it before. I suspect the anomaly is quite rare and that it might only happen with a certain set of conditions. At any rate, conditions that would not normally be encountered in the natural world.
I don't think we, in non-scientific experimenting, can actually measure the physical depth of a scarification. More importantly, I think the best we can do is estimate how close the scarification is to the seed inside by examining color variations as the surface approaches inner seed contact. Of course, colors may vary depending on the species. If you are soaking the seed in water rather than planting in soil, my prediction would be that scarification size (in diameter, not depth) would be fairly inconsequential.
