OK so after a frustrating few days I found a torrent that has 1.5.10 - DO NOT USE THE CRACK - Don't be a jerk - pay Damien for his hard work and the great software - but if you rename Audirvana Plus to Audirvana Plus 1.5.12 then reinstall the old .dmg file - it will use your existing license file as it should all be in the same directory.
Now I can add proxies again, which work flawlessly for my Teac ud-501
Awaiting a 2.0 with a nice file system for hi res