The automatic gearbox frequently upshifts in error (for example, just before a hill, making a downshift immediate) and downshifts too late when overtaking, resulting in erratic behaviour, lots of revs, and considerably more fuel consumption.
Taking this into account, in almost all cases cases, a manual transmission might be more efficient.
None of what you describe costs fuel, nor does it cause "lots of revs"? Upshifting "too much" is the opposite, it's fewer revs (and therefore less fuel used, not more)
Taking this into account, in almost all cases cases, a manual transmission might be more efficient.