There’s no right answer. Breathe as much or as little as you need to maintain the effort level needed for your race which will be very different in an Ironman to a pool based 400m sprint.
I feel somewhat embarrassed giving swim advice to a former competitive swimmer (!) but don’t overthink it, just breathe.
FWIW for longer distances I often fall into a 2/3 pattern of breathing but it also depends on whether it’s a wetsuit swim or not. I’m an adult onset swimmer and by no means a natural so the buoyancy of the wetsuit means swimming takes much less effort for me and I tend to breathe less, maybe alternating 2/4 to the left as it’s generally my preferred side. Without a wetsuit it’s harder and I’ll tend to breathe every 2. For you as a swimmer it may be less an issue.
Just do what feels right for you and swim to your ability while the rest of us flounder some way behind 