For the committed longs, I would suggest moving some or all of your stock to a type 1 account. If it ain't marginable it can't be borrowed. With 23.5 million shares short and a current short level that seems highly improbable based on available shares this add to the pressure that is just starting to brew.
Your assumption is correct. They can't be borrowed. MM's aren't in this position. This is primarily traded on the Amex with a specialist. MM's not in the business of taking large risk exposures on moves. BOEPD this stock is heading north for the summer.