You'd have to have two different pieces if you want the options that you describe. If you want to make two triangular sections, the partition would have to be the sqrt(length^2+width^2), i.e. longer than the length of the bag. You could compensate by having two pieces that either snap or velcro together in the middle to make longer/shorter pieces. I'd also put tabs on the ends and bottom that, again, either velcro or snap in Sam - I'll send you sketches when I get a chance.