Making them become a brick to reduce that lag would also be impossible, it would have to be a shape file, it couldn't be a .blb. Making the item model into say, a box or something more simple could work, but would still lag to a point. I'm also not sure if that's what you meant.
Let me explain
I drop my item, and the first place it touches, well, the system recognizes where it can place a brick(siba's small chest for example) and after it's been set down, a player can click on it, and pick it up.
If a player dies, they drop a full chest, and players can open that chest up and take what they want from it.
If they take everything, then the chest disappears.
Also, these chests are fragile, so they should have health.