Again, thanks for all of the thoughtful responses! Great tips
Swingman, I will certainly apply those. After this discussion, I
think I will reduce the size of the box of drawers so that overloading
the floor joists is not an issue. Instead, I think I will build
several smaller units around the space, including some in the knee
wall that runs along two sides (and yes, dealing with any load-
supporting-knee-wall issues, if they arise!).

Kevin