I'm sure you could get an extra set of 3A92 cams and have them ground down for an 'economy grind'. Its just a matter of if you're willing to pay for it.
A performance grind is harder since you need more material on the cam lobe. There are places known to weld additional material onto the lobe, and then grind a new profile on it. This of course would cost more since its an additional operation.
View my fuel log 2015 Mirage DE 1.2 manual: 41.7 mpg (US) ... 17.7 km/L ... 5.6 L/100 km ... 50.0 mpg (Imp)