Maltose is a little different than corn syrup . . .
Maltose sugar is (wait for it) maltose. Corn syrup is fructose. But, your point is a good one. I think you could use corn syrup and decrease sugar in other components of the recipe because fructose is sweeter than maltose.
Molasses could work but would change the flavor profile of the sauce
anyway, I'm going to go the corn-syrup route and reduce brown sugar to 1/3 cup (totally random decrease but want to preserve the amount of corn syrup at original maltose amount for consistency purposes)