What is the value to the homeowner and the value of your work? A dug out stump is better than ground-partway-down stump, if the property owner wants to plant grass/ shrubs/ trees.
Easier to handle stump grindings than a heavy, dirty, hard to cut stump.
What would it cost you, in total, to dispose of the stump, legally, at a green waste recycle (truck, fuel, driver's wages, profit...)?