Are you using Trash Guides? https://trash-guides.info/Hardlinks/How-to-setup-for/Docker/

Mounting the iSCSI to the docker host and then sharing the volumes to docker containers might not be so crazy in terms of hard linking. Though I’ll admit I’m not too familiar with iSCSI and I’m assuming it’s a block device and you create a file system (e.g. ext4) on top, where the file system would support hard links.

I hadn’t heard of Trash Guides before I first set mine up and I did it all poorly (used 2x the storage than I needed) and realised too late, so hopefully this helps!

Have you considered using docker to install it as a container? I haven’t used this one specifically but run all my *arr apps as docker containers which avoids these dependency type issues.

Sorry I couldn’t help with the question you asked though 😔