1 vote against truenas scale. I am happy now that it's setup, but it was such a pain to get working. The GUI insisted that the disks had no serial numbers, but I could see them clearly in the commandline. I had to commandline setup the zfs, which they dont doco, and it has diverged from the published BSD instructions.
I also get the impression that unless you are using commercial grade stuff, truenas dont want anything to do with you.
Do you really need encryption if its all local? You should be able to trust your network is safe, so encryption in transit is the most you need to worry about? And if your NAS is on 24/7 its decrypted 24/7 anyway, so no real win having disk encryption.