so, I attach a snapshot, have a look. this is part of book trader window, on top of it you can see Default Size, where you can modify position sizing.thanks for the post. Yes, would be great to hear the workaround in Booktrader.
currently I just have hot buttons for each quantity.
I have hot keys set for "sell at bid" and "buy at ask", specifically for BookTrader, but you can have buttons set as well.
whenever you use hotkeys or buttons, you have to make sure that in size settings you have "Default" set as size, order type LMT, and buy/sell at BID/ASK setting
https://ibb.co/9Zp7mZN