Here is the email that I got.
A change was made to the margin calculations and the butterfly trades you were look at should withhold the proper amount of margin now.
Could you try one out when you have a chance and let me know if things look as you would expect?
Sincerely,
Chris Lepore
Director of Operations
When splitting the closing of hedged sdraddles into two orders you can also close the winning side in one trade (shorts and longs) and then close the losing side in another. I'll often do this when the stock price has had a big move - closing the winning side first in one order since its very sensitive to stock price movement with its ITM, and then closing the losing side whose price moves much slower.