The Expanse is very much space opera. Don't get me wrong: I love the show. But the only real difference between it and Star Trek (science-wise) is that The Expanse has zero-gravity. It still has the inertialess movement common in space opera.
I didn't notice anything in The Expanse that contradicts the laws of motion, and it is the only fiction TV show I can think of that is careful in that way.
For example, more than once or twice a space ship is shown firing opposite the ship's direction of travel during the second half of the ship's trajectory. And I seem to recall a scene showing a ship (with only one large engine, which of course is the sensible way to do it) doing a flip at the half-way point to point the engine directly opposite to the direction of travel.
