is exlink really needed on B550 CI+ to enable movie mode?

[erdem_ua]

You can enable it from Service Menu too if you can. Later versions disable this options by graying out. So we use ExLink cable to enable this from debug menu. Don't update to latest version 2008 for CI+ because its constrained and couldn't reversed back if you install once. You can update 2007 version if you could find.

[erdem_ua]

I don't know if DLNA is enabled. You don't need that anyway if you have network access. You can mount SMB and NFS shares.
Network access available via specialized kernel hack. But Wiki page is not ready yet to describe the process.
Also don't know what 2007 version adds some options. But I don't wait such a crucial properties with this update...Thanks