I'm not sure I would call 90 days a normal timeframe for a photo. Most photo-period grows I'm aware of go out well past 110-120 days.
But to answer the first question in this ^ ^ ^ post:
Along with the first autos (Canada late 80's/early 90's IIRC) the 2 things they found were that the plants were small and not very potent.
Ever since then, to varying degrees, breeders have been looking to isolate the "auto" gene away from any other characteristics/traits that
they deem undesirable. In other words, they WANT all the other characteristics of photoperiods. Size, potency, etc. but just want to inject
the auto flowering trait. Breeders aren't looking to retain any other traits of the Ruderalis. (in most cases)
My plants usually cease vertical growth around Day 40 or so, then develop the trichome profile I desire at Day65 to Day 85.
I've had some plants become very yellow (As well as reds and purples during maturation) and some that didn't.
An scenario I've found myself in:
There have been times when one of my plants was REALLY still drinking hard during the cleanse. (which is what I call the flush at
the end since it really isn't a flush to clear the soil, it's a cleansing of the nutes left in the plant) She was drinking the pot dry
everyday. Since I knew how much water she had gone through, and I liked where the trichomes were, I harvested before a
2 week cleanse had been finished. No yellowing because the plant, through human intervention, was still getting enough of
what it needed to not start draining it's own fans as it normally would.
Ultimately, yellowing fan leaves or no yellowing fan leaves a plant can have reached prime or desired maturity for our purposes.
The way you are conceiving of crossovers to human genetics/traits and "majority rules/ 51% wins" I think is clouding the
issue and creating false equivalencies. The false equivalency being that if a certain percentage (quantitative assessment) of
traits are "like" a photo, but it has that one auto trait for photosensitivity, then why don't I treat it like a photo because that's
what it's mostly made up of. The answer is "because that't not what it is, it's something different now as a result of being
modified/crossed/combined" and that "none-apparent traits have also been passed along, like more sensitivity to nutrients"
It can't be judged or assessed by the sum of it's parent's parts. I must be judged/assessed on what it, uniquely, is.
It's not A + B = C and C - B = A, that's why different phenotypes exist. The marriage exhibits MANY different variations
just in one pollenated plant....with all the same ingredients, from the same parents. In the first cross of an auto and a photo
some offspring will be auto and some will not. This "average" is expressed in a percentage number but that's not a "hard"
number, just a probability. Once you pick out two of those offspring that are both auto and mate them together, the percentage
of offspring that will turn out being auto increases and so forth. Going to F3 usually means that 100% of the offspring
will exhibit the auto trait...but that's not a guarantee, just a representation of probability. (I think I have that right
IDK, I just get the feeling you are getting hung up on particular assumptions that are under-serving your understanding of
it. Not that I completely understand Organic Chemistry or genetics either.
There are so many dynamics at play, that either aren't apparent to the eye or aren't being considered in the equation, that
come to bear on the reality of the situation. IDK, I just feel your frustration and I'm trying to offer an offramp in the cyclical
nature of "Well, "A" seems to be the case, and "B" seems to be the case so why isn't safe to assume that "C" is the case?