Just watch out for any excessive grain that may suddenly appear in otherwise smooth areas, such as the sky or clouds, when burning in with harder grades. While burning in with various grades is very useful, I feel that if you can burn it with the grade of the base exposure, it can make the print less complicated: both to make, and to appreciate.
This is valid for those who care a lot about grain. While I don't particularly care about minimizing grain, tonality ranks #1 in my list of priorities of achievement in a print. Grain might be noticeable up close when you push your nose against the print, but tonality screams at you from across a room.
"Often moments come looking for us". - Robert Frank
"Make good art!" - Neil Gaiman
"...the heart and mind are the true lens of the camera". - Yousuf Karsh