Note that if you want to use the whole available range of a softcut buffer (or just refer to the end point) you can use softcut.BUFFER_SIZE. Actually it’s possible that this won’t ever loop smoothly since it doesn’t leave room for any post-roll to crossfade, never mind me. Or use softcut.BUFFER_SIZE - 0.1 (or whatever your fade_time is set to if not the default 0.1 seconds).