ISCSI PLUGIN - LUN BLOCK SIZE

I wanted to know what is the best method to set LUN block size when leveraging the OMV iSCSI Plugin? I am attempting to use iPXE to boot iSCSI target of a hard drive of an Ubuntu installation. I am getting errors on the IPXE client that is preventing the boot from happening. Issue seems to be related to wrong block size of the LUN. I believe my LUN's current block size is 4096, I would like to adjust the block size to 512 per IPXE recommendation to allow iSCSI based network booting.

Is there another way to set LUN block size outside of the Plugin? I looked for configuration files for iSCSI leveraged by the plugin, but they are not located in expected paths.