I do "bump" it but haven't really had those issues.
It is true...having a "small bike" and short reach has it issues. I do bump into it more when I dismount and stand over it.

I think the fuel belt one is better than the starndard bento if that is your issue. I think the small one fits snugger. But it is a hard case.
On the other hand the other one has some plastic "stays" that can be removed so it is softer sided.

But I could NOT live without it!