until the 12 month period most docs will address your concerns re: growth and density with:
"Let's wait to see the density fill in over the next (fill-in) months, and then we can address your concerns at that time."
...and rightly so.
Nothing really should be done in terms of adding more grafts before 12 months and
Nothing could be done to increase density or hasten growth but adding more grafts
but in the end, most HT are fixable if you are not satisfied
it's a 12 month waiting game for further adjustment though