As mentioned, it should have followed The Hunt for Red October model of starting off in Klingon to establish that they were speaking a different language, and then quickly transitioned into English, while only transitioning back to Klingon as needed for emphasis, such as when human characters were secretly lurking on the bridge listening in. The actors were already struggling to speak clearly in heavy makeup as is, and then to add to their difficulty by making them constantly speak an alien language they were unfamiliar with just made things worse. It was slow and stilted and didn't flow like natural speaking would, and it took me out of the narrative every time.