nope, for now i am ignoring them, (but they still exist) i did not make them, my blame in on the freenas,
all i did is to make dataset, configured max capacity and then nfs share with root:wheel and the reset is default
I am not able to reproduce this and can confirm that datasets are empty when they are created and when they are shared over NFS. What client are you using to access the NFS share?
maybe there are the outcome of the dataset? ( i had a dataset set on the same folder i configure an nfs share)
multiple clients, all debian based (ubuntu 18.04, proxmox )