"The only way to avoid terrain with certainty is to avoid it with a wide berth or by flying above it at a minimum safe altitude, whatever the flight conditions."
Flying at minimum safe altitude will not allow you to predict the downdrafts. Several accident reports show that. Few, if any, light aircraft can maintain altitude if unable to get out of the downdraft.
About 27 years ago a C177 was dragged down from a safe altitude above cloud, into the Cairngorms. They recognised the corrie they came out of cloud in. Before hitting the headwall they hit an updraft and were thrust back up clear of cloud. No damage so no AAIB report. Two very shaken guys turned back to Inverness. The wind forecast was OK when they took off.
Giving terrains a wide berth certainly works. But not everyone lives in flatlands.