Also, im not sure if the sleepdeprivation affects anything else than the health status, maybe learning too? But it would be sort of realistic addition that you learn some stuff during the day, it will be a separate progression bar that gathers when you do stuff that you learn from. There could be additional warning about sleepyness/tiredness, and after sleepdeprivation kicks in, that progress bar would slowly start to decrease unless you go to sleep. Since things that you learn during the day, is being processed in your sleep and then you actually learn it. So the progression would be added to the skill only after sleeping long enough. And if you try to stay awake for too long, it would eat away what you have learned during the day. That could give the possibility to also increase mechanics while using the grinder, and not only materials. Tough it's only needed if ore mining doesn't become more important part of the game.