The place where you suggest to have this feature is not proper, as this is just a place to convert audio file formats.
- signal level must be under (-xy dB)
- length of silence must be (> XYseconds)
In the Auto Split tool, you have these options. What you don’t have, is maximum number of splits.
This is not a simple option to add, because this would be a multiple pass operation: if 300 split files are detected (for example), this means the number of splits has to be reduced to <= 256. A choice has to be made by WaveLab: with which criteria? I can imagine solutions, but this is not that easy.
What I suggest, for the time being:
Use the auto split tool, and use the marker generation option. In that way, for some given settings, you can count how many files will be produced (counting the markers).
If the number is too high, make the split factor more severe, etc. reduce the silence level, or increase the silence time.
Try again, etc.
When you have a proper number of split files, do the real split, rather than generating markers.