Back to the original question, what isn't clearly specified is whether the gradient is required by ATC or national authority for some reason (noise, president's palace) OR is it an obstacle. Charting doesn't always make thus clear. Going back to prior life, US DOD charts would specify "minimum" for obstacle or "ATC required" for all else. Two very different problems. Average will work if it is purely an airspace issue and as long as you get to 4,000' by the required point. If it is an terrain generated minimum really means MINIMUM. That maybe how we got down into OEI problems here.