Troxism

My 2 cents: For me, mods have basically been the only way I can play the game (somewhat of an exaggeration, but honestly not that much of one), ever since the new breath effect was added shortly before 'release'. The 'fix' for it a few updates ago hasn't changed anything in that regard (I honestly couldn't tell any difference post update). It's so obnoxiously bright/contrasts so much with everything else indoors/in darkness I basically can't play with it on anymore (it actually gives me a headache after a while). Mods allow me to get rid of it (ideally I'd just dampen it's brightness by about 90% when it's dark so that it's not any brighter then the surroundings, but outright removal is close enough). My point isn't really about that specific gripe (while it is a deal-breaker for me personally, it obviously isn't for everyone), but to show that in some cases mods are basically the only way some people are able to enjoy the game, and not always because of game play changes but simply by adding what amount to extra configuration options. It's just not realistic for the devs to add configuration options for every possible player demand, and mods allow that demand to be filled. It worries me that soon enough (once there is a new update that breaks mods again) there will be no way for me to address this problem, and the game will be come essentially unplayable for me (as I don't feel like getting headaches constantly) until mod support is added (and at this rate it looks like that will be years in the future).

In that case there is an issue with your specific game, or some other setting is interfering with it as 'Low condition regain' works perfectly for me in both 1.16 and in 1.17. I simply proposed a possibility as to why you were experiencing the problem. In my experience on this forum, often the solution is something simple. I am sorry if it seemed patronising.

Aurora is always pretty random so a few days sample size isn't really conclusive of anything. The reason you are getting no condition recovery at 'low' is likely because you are only sleeping 1-2 hours at a time, and it depends on the bed type. Condition recovery is not linear, and you get more condition for every consecutive hour of sleep; you get way way way more condition back for sleeping 10 hours in one go then 1 hour at a time 10 times in a row (this was actually a method I used to nerf condition from sleep previously to make the game harder). Also sleeping in a bedroll gives less condition then in a bed (and trappers bed is magic and gives even more). Note that the game does keep track of fractional condition. But for example, sleeping in a bedroll on 'low' condition regain from sleep for only 1 hour will only give you 0.25% condition back, so even doing so a few times in a row may not actually tip you over to 1% higher. A bed would give you 0.5% for 1 hour on 'Low', but around 19% for sleeping 11 hours in a row, assuming you don't dehydrate first (depends on your thirst settings if you actually can do that even with a full thirst bad). Either way I can confirm (since that is the setting I have played on almost exlusively since the update) that 'Low' condition regain functions properly, and appears to be about half of what 'Medium' is; which is what Interloper is/was by Default. High is doubled again from Medium. So it's basically something like 64/32/16% for 10 hours of consecutive sleep in a bed, but those exact values may be off (and like I said, depend on the specific bed used as well) and obviously if thirst is set to very high you will dehydrate before 10 hours of sleep pass and lose condition from that instead of gaining it.

Cabin Fever is a mostly trivial mechanic, since you already are encouraged to do all your cooking/boiling outdoors to gain the fire duration bonus (it isn't a 'duration bonus' per say, but your fire time drops slower if it is considered an outdoor fire... and that means you for example want to make fires in the outdoor parts of caves or in fishing huts), and if you do this semi regularly (I mean, you need to boil/cook a certain amount just to stay alive, so...) you will never get cabin fever. Cabin Fever is a lot more aggressive on Interloper (if you get risk you will quickly get cabin fever if you don't go outside), so the solution is to do the above and never get risk at all. The one complaint I have about Cabin Fever is this: crafting Wolfskin/Bearskin Coats will often give you Cabin Fever if you don't take 'breaks' to boil stuff outdoors (which can be annoying if the weather doesn't cooperate and give you clear weather to use the lens, forcing you to just run out, run back in to warm up, run out to try to prevent Cabin Fever risk before it strikes, or head to a cave and chill out there). Doesn't really make sense to get Cabin Fever while actively doing something, but no simple solution either. As for 'hibernation' I mean tbh I have no idea why Cabin Fever was actually put into the game (it's mostly a mechanic that catches beginners off guard, but is trivial for experienced players to avoid). Because if it was to solve hibernation then tbh the devs should have first fixed the whole starving exploitation which was and is FAR more of an issue (literally can't believe an actual exploit is allowed to stay in the game when the fix is trivial), yet absolutely nothing has been done to fix that for years. And the threat of Cabin Fever has certainly never made me feel like I should move on from an area; I always end up doing that for other reasons (boredom, loot cataloguing ect). I mean it is what it is. This game has a bunch of mechanics that don't really make sense or actively encourage exploitation. Heck, even the recent change to make you unable to climb while encumbered once again punishes you for not starving (because meat weighs a lot and by starving you can cut your food requirement to between about 1/3 to 1/5 of what it is supposed to be saving you a good bit of weight if you are going on an extended trip). So does the 'can't rest while not tired mechanic', since starving players can bypass it (because starving lowers your max fatigue after a while, letting you sleep as much as you like at that point), while non starving players are forced to use the far less efficient pass time (that consumes extra calories and water, while again, a starving player doesn't even have to pay that extra calorie cost anyways). Anyways, I could go on in much further detail about how broken some mechanics are in this game/explain more of what I mean above, but I don't think anyone cares to read an essay and it's wayyyy off topic. As for a 'vitamin mechanic'; this would basically just arbitrarily cap survival times (when currently the game doesn't really put a cap on those at all if you play carefully), unless there was some form of respawn implemented for it (which wouldn't really make much sense). But to bring all this back around to the original topic: my feelings on Cabin Fever are a resounding 'meh'. I don't care too much about the mechanic either way as it has almost no effect on my gameplay for all the above reasons.