With lz4 compression, should I use rsync -z?

Hello:

My zpool was created with lz4 compression, the default.

I'm running an rsync backup job from another machine using cron. My rsync command uses the -z option, which compresses the files.

Should I be doing this? The local machine is compressing the files first as it rsyncs, then FreeNAS compresses the files again using lz4.

I can't help but think this slows things down for no reason. Should I drop the -z rsync option?

Thanks.