That someone who took the suit home get's called into a hunt and doesn't grab it, is a very good idea.
That should happen at least once.
Because the players don't know (like we do from reading Gantz) that you don't get a new one.
They took it with them to train. There is no danger for them outside of the missions yet, so there is no real reason why the would have it on them all day long.
Taking that into account it seems very likely that one of them might forget to grab it before they get frozen for the transfer.
It's the same with the walking out of bounds and talking to someone about Gantz.
Those are normal things to do.
Some people just try to get home, and get blown up, just like some talk about Gantz and suffer the consequence.
Most people that start hearing an alarm in their head don't think "maybe I shouldn't go any further". That Koi did was only because Hadou has read Gantz and knew what would happen if he didn't go back (but we would all have done the same).
The point is, they can only learn about that stuff if they see it happen at least once.
Just let some npc's try to get home, a character follows them to persuade them to stay and see's them get blown up. He makes the deduction, tells the others and it's common knowledge.
The same thing can happen with talking about it. On their way home a npc walks the same way as a character. He get's commentent upon the strange suit, talks about what happened and get's blown up. Again, knowledge gained.
"For Feanor was made the mightiest in all parts of body and mind, in valour, in endurance, in beauty, in understanding, in skill, in strength and subtlety alike, of all the Children of Illuvatar, and a bright flame was in him"