Sorry, I really don't agree with this suggestion.

If having such a value would actually make any sort of a difference for users, I wouldn't argue, but in this instance I really don't see the benefit of it - it just adds yet another option without adding any real value. By this I mean...

Most time that you actually want to analyse across multiple tracks, the number of tracks is probably quite small (i.e. perhaps several tens of tracks) and you select them reasonably carefully. Very occasionally you might want to analyse across more than (say) 200 tracks. Most of the occasions that you select a very large number of tracks you probably aren't interested in the analysis.

So I really don't see the additional value in providing yet another option that the user has to understand and set when a well chosen default will pretty much work equally well for everyone.

(That said, the effort to implement an option is small - so if you really really really insist, I will do it.)