To clarify the request, which I support, this would be when editing your Profile Stats and adding a custom list. The custom list then shows up on the Milestones tab. The custom list shows only the Date, GCCode, Cache name and Location columns.
The request here is to be able to show additional columns such as Log Type, Cache Type, D/T, etc.
Personally, I believe the columns I would want to display would vary based on the type of list I am showing. For instance, I've added a custom list of all my "States' Oldest Finds". It would be nice to show the type of cache, the placed date, and the region.