I dont think a lot of nicotine is lost in fermentation. I may be wrong but once ripe leaves are harvested they are at max nicotine levels for that specific plant. I think the only way a minimal amount of nicotine is lost is if the humidity is too high - 80%+ during fermentation. You will get a lot 'tobacco juice stains' in your kiln, but even then i dont think a lot of it is lost. Again i may be wrong, maybe one of the tobacco veterans on this forum can give you a solid answer.
