One thing not mentioned in this thread is keeping someone alive in jump space. The gunner position is not really needing in jumpspace. Why not have that crewmember in low berth? There is an inherent danger but, the savings in air, food and water far outweighs it. And if you have a doctor as part of crew then you would have less risk.
I think low berth would be used extensively on any ship. Crew members would have to cross train or double duty to avoid low berth. It just wouldn't make sense to have a person using up supplies without direct need to the ship's operations.
Well, in CT at least, I don't think that would be done. Even with a competent medic it's still a 4+ to survive so 8.33% of your Gunners (or whoever) will die, all the time, needlessly. It has to cost more to train them than the savings in life support. And I won't even say how hard it would be to get someone to hire on for that kind of duty (especially at the lowest pay scale, Gunners).
I've also always figured there's a minimal defrost time before the person is of much use after coming out of normal lowberths, several hours at least imo. Frozen watch procedures take this into account and take the time at the front end instead (through preparation and drugs and such) to allow nearly immediate action. Emergency low berths go the other way and take less time and prep to enter than normal low berths but with much more time and complications in defrosting, days in a hospital setting.
Then there's the usual skill rot that sets in if you aren't maintaining it (lowberths are not stasis chambers, close but not quite).
And finally where is the life support for all these popsicrews once you thaw them out? That's what staterooms are mostly about, room and life support for sophonts who do all that stuff living organizims do. So you'd need at least a single occupied stateroom for each popsicrew to have double occupancy life support rules apply (and you still need to pay that life support, albeit abbreviated while frozen, on top of the lowberth volume and expenses). And double occupancy is only allowed for non-commercial ships don't forget. In my opinion, if I'm already paying the salary, and have a stateroom, and some of the life support to factor, why go to the extra expense, volume, risk, and everything else (including training, hiring, and paying factored replacements for the lossess) to complicate it by carrying needed crew in lowberths just because they aren't needed the whole time?
Would you put Pilots and Navigators in the same category? Heck you only need the Navigator to plot the jump in the rules. Just thaw them out every two weeks for how ever long it takes to plot the course and keep them on ice the rest of the time. I'm sure they'll like that.
So, imtu at least, no, lowberths are not routinely used in such a way. Do note I said routinely, there are always going to be some circumstances where something very like that may happen.
