For BTO it calculates using the ASK instead of the BID, for STO it calculates using the BID instead of the ASK. Intended?
I do not believe that you are right. The way C2 calculates open position P/L is to determine the profit or loss if the position were closed at the market.
Thus, if you are long, you would need to sell your position, and so we use the bid. If you are short, you would need to buy back your position, and thus we use the ask. If you can point to any specific instances where this rule is not being followed, I’d be interested in knowing.
Do keep in mind (as I pointed out to another user earlier this morning) that we can’t use real-time prices when displaying positions (since we don’t pay the exchanges in order to do so) but we do use real-time prices internally.
I very well could be wrong. It may be because of the delay that I thought it was doing the opposite. 
