One also doesn't need to click on the tab to activate it. Just cursoring over the ribbon and using your mouse wheel will advance through the tabs.
And technically speaking you can make a single custom ribbon tab that has the buttons you use the vast majority of the time right there.
Taking the Annotate tab for instance, I know I would hardly ever use the icon for: Remove All Jobs, Remove All Breaks, Delete, Draft Group, Relate View, Relate to View, Relate to Object, Unrelate, Ordinate Dimension, Model Datum, Draft Datum, Symmetry Line Axis, Cleanup Dimensions, Attachment, Move to View, Move Special, Move to Sheet, Text Style, Line Style, Arrow Style, Repeat Last Format or Hyperlink. Some of that stuff is simply easier and quicker with the RMB.
I haven't tested extensively but what I have tested makes it seem like a custom tab doesn't care what command you're trying to use.
For example, I created this custom tab and the commands seem to operate without complaint, without switching to the proper default tab and without holding the Alt key. I could also move some of the lesser used functions to a group overflow area.
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Just food for thought.