When to include border for conversion

My experience so far is that in scenes with very limited colour variation, the conversion including some border is usually better. Just recently had some shots taken during a flight (lots of blue sky and some clouds) and the pre-cropped conversion looked really strange.

Now I usually start leaving some border when I know in advance the image is quite monotone. Admittedly usually I still do a virtual copy check without boarder to be sure I am better off :wink: