The mini has 'true' optical out. Mini-Toslink is Toslink, so it's just a matter of buying the right optical cable.
DD/DTS 5.1 is a limitation of Toslink. If you want 7.1 or the newer lossless codecs, that requires HDMI or an conversion to multichannel analog audio on the device (some HD-DVD players did this, back when that was still a thing :)