When planning a new trip‌ I frequenty find myself flying around with Simulator just to have the beautiful visibility that TerrainSafe offers. I live near the mountains and it's often hard to see with the normal map how wide valleys at a certain altitude are and which valleys are well connected to each. Just the other day I went from Munich to Basel and had to find a good route under Zurich CTR. 
W‌ould it be possible to enable TerrainSafe in planning mode as a simple overlay? This shouldn't be too much work since it's already implemented and it would make planning so much easier. 
T‌hanks! 

We've thought about it, but of course it would require the input of a specific altitude. Not enough people have asked for it for us to give serious thought to the user interface we could use for configuring this sort of functionality.