We are homeschooling a child who has significant strengths and significant weaknesses. We have focused on getting his weak areas up to the level where they won't unduly impact his ability to function in daily life, to the extent we can without unduly cutting into his time to pursue his passions. We have found that we can leverage his strengths to help him find ways around and through his weaknesses.
If your child doesn't have areas of weakness that rise to the level of disability, I wouldn't worry about forcing them to try to be "well-rounded". I would focus on making sure that they have regular exposure to a wide range of unfamiliar topics and experiences, because you can't develop passion or skill something you've never tried, and ensure that they are allowed to pursue things that they find they enjoy but don't easily excel at if they choose.
