Don't have time atm to post this to email yet, but will after work.
The problem is when making piles (ie of grass) on the ground, the way it stacks is still bothersome (in my view anyway).
When you get quite a pile on the ground; which I currently have 3 high 7 wide, taking a stack of grass from say the middle means that you can't drop other items to this auto-stacking pile.
Attempts to fix this includes removing two more 4.grass bundles and redropping them, however when redropping them, the game seems to believe that the items removed the middle of the stack are there, and skips those that where removed.
The way items are dropped seems to be erratic still, and I hope a container (ie chest) can accept world items such as Grass as the way items stack seem to be annoying, more so if you remove a item from the middle of the stack.