Those that are saying there wouldn't be enough time, are kind of wrong. There is enough time.
Not enough time to switch on EVERY shot that would just so happen to come to the other hand.
More than enough time to do it when you CHOOSE to.
My shots are equally as hard with each hand. But it's something I've always done. I don't need to think about switching, I've perfected when to switch, and when not to. When to just play lefty, and when to just play righty.
A pro has more than enough time. Especially Nadal.
When he plays baseline shots with his left, and then has to run over to hit it with a two handed backhand, all he would have to do is not use one hand.
The only problem would be the grip he chooses. Since he is planning on going back to his left hand, he doesn't use his right hand on the lower part of his grip on two handed BH.
If he WANTED to, he could grab it lower on the grip for the right hand, and just use his right hand again for the next shot if there wasn't enough time to choose.
But i'm talking a choice, and not a habit. If you have a habit of needing to switch you would lose. If you can choose when you want to do it, it's an advantage.
Nadal approaching net could hit a big forehand LH FH cross court and it would be a winner, we've seen him do that. Imagine if he had the time to run to the net, switch hands, but it's on the AD side, and uses a powerful RH FH crosscourt.
You guys should try it at least once, even if you can't swing right. Just see if you had enough time to switch on at least ONE shot. I bet you will notice you have lots of time on SOME shots, it's just hard to execute for you.