Why are we making the squad do Navigation skill tests?
The trip takes 12 hours, 10 if they do well at Navigating, 14+ if they get off-track or delayed by encounters - but who cares?
These checks should be made relevant or discarded as they currently serve only give the impression that the Navigation is a useful skill.
The same goes for the Navigation skill tests to find the wreckage. If they fail the check, does that mean they miss the encounter or simply have to try again until they make it? If the later, what is the point?
My suggestion is to give consequences to the checks:
The trip takes 12 hours so give more emphasis to the start time of the mission (morning or pre-dawn). The trip can then arrive at the refinery at night if they make normal time, a couple of hours before dusk if they do really well, or not until dawn if they are too tardy.
Perhaps give additional consequences for doing well or doing too poorly. A positive consequence might be a depletion of the refinery garrison as it leaves to go on patrol. A negative consequence might be encountering a patrol from the garrison which, if they do not silence, will tip the garrison to the squad's presence.
The time should perhaps also impact the amount of prep the squad has before the warboss arrives.
This allows for a difference in tactical thinking for the group with a gradual reduction in options depending on how they do.