If you are over extended, re-evaluate your stocks and sell off the ones you want less than the ones you desire to buy. Reshorting is a good way to convert your gains into liquid $. if/when I do this, I simply press the sort by gains column and start scrolling down looking at the shorts. Personally, I don't worry about whether or not a stock is a slow bleeder when I reshort.
Before reshorting, I recommend you deinvest in stocks by your own priority and in stages. For example, I will get rid of daytrading and news stocks before long term holds. I might consider which starbonds have high value and low dRoi. For me, anything more than 2-2.5 mil SBO value becomes at risk of being let go to free up money. I also look at derivatives, slow bleeders, long term holds with no release date, funds over 100$/share etc...then there is reshorting.
Many options exist in managing your port to make it a more efficient earning tool. Invest wisely and deinvest with even more careful consideration. You are spending 1% comission to invest, but 2% to sell off and reinvest. Make sure it's what you want to do..
Good luck in making your decisions.