I don't think it's worth overclocking RX5700 for two reasons
1. It will draw more power, you want to lower the power draw for better returns and avoid spending more on electricity
2. RX5700 are very hot, overclocking them will make them more hotter, this can shorten their life span
quite the opposite . what have you been smoking.
clearly we are under volting making things not as hot.
smoke another!!!!!!