The problem with free'ing the %is_selected is just one symptom of a poor solution that doesn't scale.

The problem with freeing that is a problem with adding traits to a language which doesn't natively support them. It has nothing to do with whether or not the concept is appropriate.

As for the rest of what you typed, it might be a great way of looking at the problem but it's completely irrelevant to my specific coding problem. With runtime traits, my code is cleaner and easier to read. Solutions should be created to match actual problems faced, not "what if" scenarios -- unless those scenarios have a realistic chance of occurring. For the purposes of the code I was working on, it's been used for years and is quite stable. Your scenario is highly unlikely to apply.