Sorry, at this time there's no way to change the timer back to the default time point system. The best we can do right now is the option to disable time flowing in menus, which will make the timer only run while you're actively struggling and thus will function pretty much the same way as vanilla D2, but not exactly. Making the time point system work with our other modifications such as the arousal system would be challenging, hopefully someday we can figure out a solution.