As part of the Universal Account service, we are authorized to automatically transfer funds as necessary between your securities account and your futures account in order to satisfy margin requirements in either account. You can configure how you want us to handle the transfer of excess funds between accounts on the Excess Funds Sweep page in Account Management: you can choose to sweep funds to the securities account, to the futures account, or you can choose to not sweep excess funds at all.
In particular I would like to make the system a lot faster, since it will allow parameter searches to be carried out in a reasonable time. While Python is a great tool, it's one drawback is that it is relatively slow when compared to C/C++. Hence I will be carrying out a lot of profiling to try and improve the execution speed of both the backtest and the performance calculations.