Sharing files from custom url in Subsonic 6

Has anyone figured out how to share files when you have a custom URL instead of a xxxxxxxxx.subsonic.org address on Subsonic 6? I was able to hack together a workaround for versions 4.x and 5.x but the interface rewrite for version 6 changed some things and I'm unable to figure out why it no longer works. Anyone else had any success sharing from a custom url?