I think this may be more of a feature request.

Currently, mp3splt seems to allow splitting on fixed lengths or silence detection.

Is there any way to combine the two?

For example, I have an application where I need to split an audio file ideally on periods of silence, but the split files cannot be any larger than 1 minute, so if the silence splitting finds a chunk that's, say, ~3 minutes long, it'd be nice to have some sort of "--max-seconds=60" option to force it to automatically split that into 3 chunks, even if there's no silence in it.