Yes, edge cases can make features pathological. That "simple feature X" might be simple in isolation but when crossed with "simple feature Y" may cause your ed

Yes, edge cases can make features pathological. That "simple feature X" might be simple in isolation but when crossed with "simple feature Y" may cause your edge cases, test code, and linecount, to explode. Not all features are a simple additive amount of work. Usually the work to add a feature is relative to the other features that already exist within the system.