I haven't completed a rotation yet to be able to say, but some info that may help:
If they have a Romance Dynamic, that autonomy should follow them into the wild, not only when they are actively being played, though I don't know if it dictates every interaction between a couple, or just influences interaction type percentages. Having a Steamy or Wholesome Dynamic should help increase positive interactions between your sims when they appear in the world.
If they have high Romantic Satisfaction when you rotate away, they should passively gain pink bar/romantic relationship level over time even when not interacting, which could counteract self-sabotage, at least to the pink bar.
The impact I would worry about here is the damage to Romantic Satisfaction by being Mean, which could possibly cause a break up (if enabled in NS). I know they can autonomously break up when active as it's stated in Options, but the inactive NS description doesn't say anything specific about break ups, just relationship damage.
It's something that will take time to be certain of, I'm afraid.