I'll be general, but aren't the furnaces what got GTAT in this mess? The huge loans to facilitate developing, improving, enhancing, etc the process and the furnaces are part of what that yielded. If we sold every one of them and that only covered 75% of the debt... imo that's a good position, because of all the other tech under GTATs belt.
The only way to eat an elephant, one bite at a time. Get the debt gone or reduced and everyone will breath more easily.
I know that's not a perfect road while in BK... but it should go a very long way for everyone's comfort level, business dealings, inter/extra company relations, etc. etc. etc.