The delay before conceding was added after enough forum users requested it. The primary reasons were to avoid conceding too fast before they had a chance to stop the bot themselves, prevent conceding at the same time as other bots, and to avoid bots having a distinguishable pattern of conceding so fast after the game start without doing any other actions (to try and improve security).
For now, that won't change, but we'll think about adding an option if enough people want it in the near future.