Comment 7 for bug 1799574

Using samples from the start is problematic IMO as users probably don't expect it, and if the do the result is unprecitable because that range is not visible on the waveform.

Extending the loop-able range beyond the track and filling that space with silence would still be my preferred solution because you would get what you see: silence.
If the engine could do that the remaining question is just:
how far may the loop to span behind the end to avoid long silence?

what about limiting that part to at most the half of the desired loop?
Example:
* X beats before end, X=track_end - play_pos
* attempt to set a loop of N beats
if (X > N/2) {
  beatloop_activate
  return
} else {
  N=N/2
  // repeat
}