If it is the final split, the timer will stop automatically at the end of the cutscene after a pantheon.
For example, when running 112, if I don't add a bench room split, it will be like this:
- Sly (Pantheon)
- Pure Vessel (Pantheon)
- Absolute Radiance (We don't need an autosplit here)
After beating pv in p4, it will turn into the final split 'Absolute Radiance'. Then we have a cutscene which involves the Hollow Knight, the Knight, and numerous other Vessels. After the cutscene, the timer stops automatically.