I'm working with 80/20, a material that's cut-to-length for building . I could make a new part file for every length that I need, but I don't want to create a ton of parts.

I'd rather have on part for each profile (1010, 1020, etc.), then add a configuration for those each of those profiles for the particular length.

The problem I've got is that any time I edit the extrusion length for one configuration, it changes the length for all the other configurations. I tried making extrusions all at the same "tier" of configurations. When that didn't work, I deleted the base extrusion feature, keeping only the profile sketch, then added derived configurations. The derived configuration, I thought, would keep the sketch and allow me to create a unique extrude feature in each sub-configuration.

This is not the case. Instead, when I make an extrusion on one sub-configuration, it creates the extrusion in the parent (Default) configuration, which then gets suppressed. The other configuration then also shows the suppressed extrude feature.

What am I doing wrong?