It probably depends on the tab that you are trying to modify. Some tabs allow you have more control than others. The myUSI tab, for instance, has a few channels that can not be deleted, but they can be moved around. Still other tabs have channels that can’t be deleted or moved around, and others still give you free reign to do as you please.

If you are most concerned about total custimization, the best option is to create a new tab and then add channels and columns as you see fit. You can ultimately create whatever suits you best. If you end up using this new tab primarily, just make it the default and it will be opened whenever you log in.