For balanced exercise on both sides as well as THB being more reliable than OHB, I opted to learn THB since the beginning, which is three years ago. However, it always feels unnatural to me. I've experimented with all kinds of grips and no matter how I hold the racket, either my left wrist feels awkward or my right wrist feels awkward. I cannot find a way to hold the racket where both wrists would clear comfortably.
My forehand is pretty good and mechanically sound. I can even hit OHB simply based on feel despite never learning or practicing this shot at all. Slice is also no problem. My coordination on the right side is pretty good likely as a result of playing table tennis when I was young.
However, I don't think this is a left side bad at coordination issue. At this point I just cannot hold the racket comfortably in a two-handed backhand swing. During my swing my left palm would always leave the racket because my left wrist wouldn't reach the required angle to stay on the racket. So I think I've basically been hitting a right-side dominant THB all the time. And the only usage of my left hand is just making the swing more controllable. It does not add any power to assist the backhand. In fact, I feel it's actually holing the racket head back, not allowing it to flow forward naturally as I would in a OHB.
I looked up ATP backhand slow motion on YouTube and as far as I can see, all Pros keep their left hand as well as right hand completely on the racket during the entire swing. So, I tried adjusting my grip to prioritize comfort on the left wrist so that it would clear during the swing without having to leave my palm off the racket. And now, my right wrist ulnar side starts to hurt because it would not clear comfortably during the follow through. In fact, my right palm now has to leave the racket in order to not break my wrist.
I've never seen any videos discussing this sort of issue. WTH is going on????
TLDR: I'm right-handed. I can swing OHB and also a left hand forehand comfortably. But I cannot find a way to swing THB comfortably. Either my left wrist feels weird or my right wrist feels weird, or both feels weird. And now I've completely lost the plot on how to hit THB and my right wrist ulnar side starts to hurt. Even shadow swing would make my right wrist hurt at this point.