Given the same information, any course change would be the same one, every time, even if they tried to randomise it (randomisation in computers is just based on set criteria, after all).
But the criteria needn't have anything to do with the situation.The course could be set by a random count from a random process at a specific moment - and the moment would depend on when our heroes asked the computer to choose a course. Since we know the loops are non-identical in content (the heroes don't make the same movements and don't speak the same dialogue), the count would not be the same from loop to loop.
Of course, the heroes don't know that the loops are non-identical. But if they proceed from the assumption that they are identical down to the millisecond, then there is no hope at all, no matter what they do or don't do, because perfect predestination is guaranteed (as it's the only possible way to achieve identical loops).
The heroes really have every motivation to think that they are merely stuck in a unique loop, or that a series of loops is taking place but merely around a "strange attractor" of some sort, with multiple different loop options producing the same general result of re-looping, but a suitably
different take resulting in a breakaway.