A crash happens when inserting stone and grass into a relocator pipeline going towards one chest with a spread module. I would assume that this happens with any other 2 items as well. The second item to attempt to enter the inventory is also deleted from the world, as far as I can tell.

Crash report: https://gist.github.com/8189393b20fa954beb25

Also, for some reason, items are inserted from the end of the chest's inventory (last slot) not beginning, like I would expect.