For example, if one B738 has 8 t/rounds a day, that's 80 minutes saved but can that time be profitably used....
Apparently so. There are circa 60 737s flogging around in mainline. If by using this only half of them can do an extra sector that's still 30 additional sectors a day- nearly 4 aeroplanes. Even if only 1 in 4 get an extra sector that's still 15 sectors or nearly two airframes.