If you customize columns in the list of emails for a specific account (and within an account individual folders, such as inbox, sent, etc) that remains specific to that. So if your preference in the ways columns are displayed and ordered is consistent across folders and accounts, you manually have to do it for each of them. Of course it's even worse if you use TB on multiple computers as you have to do that all over again. Saving the format of the columns to display as part of your profile would be quite helpful.