Multi-round combat is mainly the player full retreating to reset peak performance as soon as it expires, not the enemy. That is the main reason to edge-camp (if fleet is not strong enough), to retreat ships immediately after they run out of peak performance. AI will happily stay and play chicken with PPT/CR wars - don't play that game! Happens if too many smaller ships (Drover, any ship with Unreliable Subsystems) or phase ships (Doom) time out, or if map size is small (about default size) that fights are a long drawn out series of duels.
If my lose my Doom support (or other critical ships) because they time out too soon, and I need them to win, I will full retreat to reset the peak performance clocks for the whole fleet. Rarely, I may full retreat to reset command points too. (I only did that once or twice.)