I have cryptsetup, otherwise I wouldn't be able to boot my system. Root partition is encrypted too
Use of systemd automount explains much. Location is available. It's in /etc/luks-keys/ and I have one big encrypted partition for everything (except /boot). So if it can read cryptab, it can read key. Output of my lsblk may visualize it better:
sda 8:0 0 238,5G 0 disk
├─sda1 8:1 0 1M 0 part
├─sda2 8:2 0 4G 0 part /boot
├─sda3 8:3 0 230G 0 part
│ └─data 254:0 0 230G 0 crypt
│ └─data-root 254:1 0 230G 0 lvm /
└─sda4 8:4 0 4G 0 part
sdb 8:16 0 1,8T 0 disk
├─sdb1 8:17 0 931,5G 0 part /run/media/beniamin/HDD
└─sdb2 8:18 0 931,5G 0 part
└─luks-hdd 254:2 0 931,5G 0 crypt /run/media/beniamin/HDD_ENCRYPTED
That's with HDD manually mounted. I'll check crypttab with line you wrote, and come back soon with result
I'd rather keep location, as few configs depend of it. But if there is no other way, I'll just mount those drives in /home and edit them
EDIT. I checked this line and it works just as it should. But with key it gave me error "failed to connect with lvmetad". But I have it enabled in runit. I guess it's starting later. Can I change it?
EDIT2. It actually works, the issue was nofail option in crypttab I also managed to workaround mounting via udiskie so it mounts in the paths I want