I have one for my big girl that she just barely fits under, she loves it. One end is pushed up against the side of the tank, with her cocofiber built up against the glass, so she feels secure. Her water dish is right outside so it feels more enclosed.

On the other end I have a black shoebox with a hole cut in it that she squeezes into. I decided I was going to stop being so picky about things looking natural, haha.

I wouldnt use exclusively the half log hides because like others have pointed out, they typically don't provide enough security. The rock hides are pretty cool, I use them for some of my other snakes, I imagine if they're the right size they could work for a bp.