This is a list of most TS4 UI SFX found from the UIControlEventMaps in the S4Studio Game File Cruiser. This includes all buttons, modals, phone/text notifications, most CAS sounds and Build/Buy placement sounds.

The Instance IDs correlate to the AudioVocals (Samples) which can be overridden. If you would like the ID of the AudioConfiguration, hash the name, for example: ui_speed_1x_from_greater = 29D5D2C4FDFA6D8F. You can convert sounds to mp3s and back to the game's format using the TS4 Sound Tool and ealayer3.exe.

Special thanks to thepancake1 for leading me in the right direction.