I am not sure this is actually the correct reply.
Cubase works with audio files, clips, events, regions and parts.
An audio event, that can be seen in the project view, is a reference to an audio clip. The clip itself refers to one or more audio files.
If you use VariAudio it seems to analyze the entire clip length, not just the bit that is the event. So, adjusting the event length doesn’t have any effect on the time it takes to analyze the audio as the clip has the same length as before.
If you then perform a split and bounce you will effectively create a new audio file and a new audio clip, which will have the length of the split event.
If you then open VariAudio it will not take as much time to analyze as it analyzes a rather short clip.
Maybe this helps in growing some understanding how Cubase works: