bug: account window: expand (+) works, but collapse (-) does not work. (my OS: Linux 64bit) shortcoming: calculating the margin impact for own order sitting in the exchange orderbook is not possible. shortcoming: calculating the margin impact for a single position in the portfolio is not possible. Ie. trader needs to know how much margin would be released if he/she closes that position.
Definitely possible using two-step order transmission: right-click on the open position, click 'Close', and the order confirmation panel will be displayed, with the margin impact post-action shown in the bottom right quadrant.