Yes, it is. Generally it is a good thing to not only be able to play it in tempo, but to be able to play it in tempo without strain. Without the playing affecting your breathing. When you can concentrate on other things and still get it done (because in the actual performance you’ll need to concentrate on different things than just your playing and still get it done). And for this you need to make sure you never go to your limits. Make sure you’d be able to do more than what’s required.
But at the same time it is important not to unlearn how to play it in correct tempo. Make sure that you are technically able to do it, but make sure you do not nail yourself down to the speed.