More interesting than running large simulations proving the books wrong under some reasonable assumptions, would be to run simulations searching for assumptions that would prove the books right. Some of those assumptions could be reasonable too.
That actual play breaks limits is an intentional and desirable part of the game, I think.
Their LR fails and they get that 5th decrepitude then. Though they have found that depending on Vis availability an older Magus might not have enough Vis to recast their LR. Other issues they have found are that enough if there is enough Vis to recast the LR, it might fail again within a few years if its level leads to marginal rolls.
Most of the sims I am talking about the vast majority of Magi create their own LR, rather than using a specialist. Some are not even coded up with the option for a Magus to hire a LR specialist. This pretty much puts a hard cap on how effective the LR will be for most Magi. In a Saga in which going to a LR specialist is common, then the average lifespan of Magi will increase.
I think simulations assume that magi are highly driven to live as long as physically possible. Which is a pretty dubious assumption, as most people are more driven to live as well as possible than as long as possible.
For magi, that means all the extra study/vis involved to have great longevity rituals will be spent instead on something the magus really wants.
You would be wrong there. You can dig up the old threads on the forums discussing the simulations (with comments from their writers) and you will find that if anything they went towards the low end of LR power. The fact that the vast majority of Magi in them are dying because of (repeated) LR failures also is at odds with what you are saying.
It is not that hard to generate a combination of LR and Living Condition Modifiers that is powerful enough that it will last beyond the point the Magi who has it could expect to survive going into Final Twilight. You have the bonus from your Familiar, Quality of your Covenant (and bonus for Magus Lifestyle), part of the Health stat of your lab (which can be easily boosted by Enchanted Items), and varies other bonuses (such as food quality, medical regimen, exotic blood, etc). And if all that wasn't enough, you could go to a LR specialist.
The simulations meanwhile had no (or limited) LR specialist, with (nearly) all Magi creating their own LR. Between the LR and modifiers most of their Magi hit +10 with the ones having favorable Arts in the +15 range. Some small fraction (in the few % range) would have around +20 total.
Yeah, maybe I didn't make my point clear; the simulations can't account for magi that don't 'play it safe', they just give you an average for magi who DO play it safe.
I can see many magi ignoring Warping and Decrepitude in the way that modern people ignore their own health; until a serious issue pops up, they just live the way they want to and don't take care of themselves properly. Unhealthy laboratories and overtime schedules might be more common than you'd think. Bad laboratory Safety might be more common and young magi might engage in Original Research recklessly.
If all magi were highly personally responsible and cautious about their health and magical welfare, yeah, the hermetic average longevity would be quite high as the simulations suggest. But I think it's likely that a lot of magi live recklessly until they have a serious Crisis or bad Twilight that makes them think "Yeah, time to slow down and take care of myself a little better". Those guys will drag the averages way down.
You should really go read the threads on the simulations, since this is the opposite.
Most of them key up Magi into several categories of behavior, from risk adverse to risk seeking. Most of them will kill off Magi in adventures, random accidents, "Acts of God", combat, etc.
I'm not even talking about people who get killed off my misadventure, I'm talking about people who just don't start taking care of themselves until they start suffering real issues.
Don't really know if the simulations had magi who sorta were careless about LR/Warping until it bit them in the ass.
They are all coded differently. I know the big one everyone spent a long time messing with and playing with does have Magi who are rather careless with Warping.
It was originally written to be a "Order of Hermes" simulator as a whole, so it spits out a massive amount of data when run. All the Magi in it setup/join Covenants, conduct research, study books, write books, study vis, trade books, trade vis, design spells, enchant items, take apprentices, travel, adventure, etc. The coder actually included a "wear & tear" sub-process for books to reduce the total of them since he said it got out of hand when you ran it to simulate 450 years.
I actually like exporting the books, since it gives you an idea of all the text that would be in circulation.
The code is open source and on a git.
Curiosity
In these simulations of how long a magus can live, do any of them include the time spent in temporary Twilight? Surely that would add a few years?
The big simulation I am talking about isn't about "how long a Magus can live", but rather it is "simulate the history of the Order from founding till (date)". It is not optimized to make a Magus live as long as they can and during most runs covering 450 years (Founding to standard start date) your oldest Magi will make it into the low 200s. So out of the roughly 14,000 Magi simulated in a standard length run, you will get a hand full that makes it into their second century. Something in the less than 0.1% of simulated Magi.
As for your specific question, I do not believe it calculates the time spent in Twilight, since it is only concerned with the total warping gained and if this would be Final Twilight.
On a side note, we already know that a Magus setup to avoid warping can last up to 275 years past the start of using a LR before they have a chance to enter Final Twilight. If they have SFB, they could take their first LR at 50 and thus be up to 325 before they have a chance to enter final twilight. You actually don't need an exceptional LR, only a good one (say in the Lab Total 100 range), since you can make up all the other modifiers to the roll from Covenant Living Modifier, Magus Lifestyle Modifier, Familiar Cord, SFB, Lab Health Stat, and the varies diet/lifestyle/medical modifiers. Lab Health Stat is a big one, since it only requires a level 40 enchantment every decade to keep up with the Age Modifier.
For how many decades are you able to keep up the good and plausible narrative about these items? What effects would you use?
Light, temperature (heat and/or cooling to optimal temp range), air (quality, scent, removing fumes), baths, removing excess humidity, effects for a more tranquil environment, effects on the humors, cleaning, etc.
This isn't really something I have tried in game or from a thought exercise so all of those are possibilities I came up with off the top of my head.
Kinder than me. I'd be applying a diminishing returns effect.