If you told me that you just need to complete the beautiful swimming distance despite the time. Then you keep beating 2 beats but note you must beat 2 beats at the right time.
I say that the 4 beat is suitable for unilateral breathing. Many people in the movement, novice swimmers or not from a young age are still familiar with breathing on one side, so this technique is quite suitable.
Note that the beating foot must be very strong and effective because it is followed by a long slippery passage. However, if you want to improve your performance, you should consider upgrading to a 4-beat type of foot beat.
I personally think that when you beat your foot 2 times, not necessarily you have saved a lot of energy compared to the efficiency it brings. Beating 2 beats gives you a strong advance but then you drift too long and almost stay still for the momentum that you just tried to create.
The 2-beat technique is also very difficult, but if you do it incorrectly, it will cause jerky movements, not smooth and I think it is laborious. Swimming rhythm 2 compared with nhip 4 or 6 is no different than running with low cadence compared to high cadence keeping the same speed.
There will be many people ask that if you swim for so long, you can beat 4 or 6 beats. Yes, it is not wrong but when you want to go to another level, you want to swim faster. It is imperative to upgrade your foot to a new level, beat 4 or 6 beats but still recover in time for the following 2 subjects.
Swimming in particular is a process with many options and changes. Wish you find the best method with you and enjoy the change.