iSCSI on TrueNAS and choosing a secondary filesystem

I'm currently building a server, and one of the plans is to allocate a load of space for an iSCSI share for Steam games. Currently I've got a lot on mechanical hard drives and SATA SSDs on my main PC, and with a 10G link and a bit of tuning I can probably get better performance over the network than I can from the majority of those drives. Plus it's cool!

The biggest issue I'm having however is figuring out which filesystem to use on the block device, because from my understanding it's essentially a nested filesystem.

The server will be running ZFS, and I'm planning on running the zvol with lz4 compression. I'm wanting this share to be usable across both a linux and a windows install, so the best choice is probably btrfs.

The question here is how exactly do I go about configuring the btrfs filesystem? Like ZFS it supports compression and deduplication, but I'm assuming that it's entirely superfluous and if I was compressing with btrfs then ZFS would just be trying to compress without success and wasting a load of cpu in trying, but is it then possibly worth disabling compression in ZFS and just enabling it in btrfs?

I'm assuming the answer is to just disable everything in btrfs, but I'd appreciate a sanity check.

Thanks!