I personally think its bullshit.... Who came up with the 4000mg sweet number? Maybe it really is 4g to hurt your liver but I honestly think your body builds a tolerance to apap.... Why wouldn't it? Hit your thumb with a hammer then do it again and again! After a while you can take more and more pain sooo in my thinking since I started at 4 pills 5/500's and worked my way up to 8 5/500s and then started taking them more frequently and beating on my liver witch is strengthening my shit so maybe my personal number is 15g of apap is safe?? Huh think of that one??!!!
Nope, that's not really how these things work. With your example you're only referencing the amount of "pain" one can withstand which is subjective and has nothing to do with actual damage and a lot more to do with a certain persons threshold. If you smash your thumb lightly with a hammer and do nothing, then half force 3 times and break it 3 times, and then one day decide to hit it full force and completely crush it, effectively amputating it because it is so mutilated you have still fucked your thumb up 4 different times. Yea it might still be there, or rather the remnants of it may be there, but it doesn't mean that everything is all good, obviously it is not. The same goes for your liver, just because you don't feel, or see damage doesn't mean you aren't causing any with apap doses of 15g. This shit I'm typing doesn't even really make sense because your example is so stupid.
Anyways, yes OP, you are good. Since you CWE the apap is really a non-issue (not to mention you mentioned you are not a chronic user), and because it has been about half a day since you dosed, the first system is well past it's half life and working it's way our of your system as we speak. The second dose will likely not overlap with the first at all since it has been so long. And btw 35mg of Hydrocodone for someone with no tolerance, in my opinion is a little on the high side, not that that's a bad thing. Could mean you just enjoy the opioid high a lot, you have a high natural tolerance, you generally just handle "intoxication" well, or any number of things. Now 70mg of Hydrocodone for a intolerant user (if the doses were gonna overlap) would probably be quite a bit too much, although I don't know if it is OD territory at all, it would probably make an intolerant user feel quite uncomfortable and nauseous.
And back to the debate about how much apap is "safe" at once, it's really one of those things that will never be able to be precisely defined. I mean, I'm sure an LD50 has been established, but those really don't tell you anything about a drugs safety with concern to repetitive low doses. How many beers is "safe" (strictly concerning toxicity to ones liver). How much damage will10 cigarettes a month do? How much coke on the weekends is it gonna take to ruin one's nose over time? There are two things I know about all these questions. One is that even highly skilled, knowledgeable and highly trained doctors can only estimate, there is no definitive answer to these type of questions and a big part of that is thing two. Which is that some peoples bodies will react differently, and some will be damaged more, and some less, and often times it is never know why. That being said, I think the 3-4g a day number is probably pretty conservative on the part of the CDC or whoever the fuck set the standard. They just generally operate in such a way. They don't wanna take the risk of being somewhat liberal in their "damage estimates" because in the medical community, any damage is no bueno. As an example, you will never hear the CDC state that smoking a couple cigarettes a night, a few nights a month when you're out at the bar won't do much damage because that makes it sound like you can "get away with it" if you just do once.