Building Tweaks is a mod to improve your productivity by changing how the user interface works. You can enable or disable tweaks in the settings file provided by the game. Currently there are two "tweaks" available:
Belt Planner follows Multiplace setting
If you enable Multiplace in the game settings, meaning of the belt planner key will be inverted: When Shift (by default) is held, belt (and wire) planner will be temporarily disabled, otherwise it stays enabled. Because such behavior may be uncomfortable for some people, this tweak is turned off by default.
Keep selected building in Map Overview
By default when you zoom out far enough, you will enter Map Overview mode and the currently selected building will be discarded. This tweak allows you to keep the selected building even after entering and returning from the Map Overview.