Non-Looping Scr Lock

[KasumiArai]

Given a song with two patterns:

1. Scr Lock Off, Loop Off: NitrousTracker will follow playback and play pattern 0, then pattern 1, then pattern 0...
2. Scr Lock Off, Loop On: NitrousTracker will follow playback and play pattern 0, then pattern 0...
3. Scr Lock On, Loop Off: NitrousTracker will not follow playback and play pattern 0, then pattern 0...
4. Scr Lock On, Loop On: NitrousTracker will not follow playback and play pattern 0, then pattern 0...

I would like for behavior 3 to have different behavior from behavior 4. Ideally behavior 3 should not follow playback, but play pattern 0, then pattern 1. I'd like it to be possible to display pattern 0 for editing, while pattern 1 is playing, basically.