I don't think there is ever objective biography. Our vision of our subject is always shaped by who we are. So I do, of course, think the biographer's view is always something to keep in mind.
In an ideal world, the perfect biographical subject would have been the star of his penmanship class at grade school - and would thereafter write an English that positively sings.
No biographical subject is ever on hold with the orthodontist. If there's a dry spell, it's your job to curtail or eliminate it.