I feel pretty much everything wrong with what you said.
Sophia does not see Dylan as a man because he is her SON. No mother sees her son as man just because he is good at sports, or got 3 goals or sneaked in a kiss. That kiss didn't even last a second, what passion would be in it.
All of this happened at a very initial phase of the Dylan route, where Sophia only saw him as her son. It is After the bikini event Sophia started seeing that her son can also be mature and not just a whining boy.
People who believe Dylan's personality changed all of a sudden and it was unrealistic. How much do we know Dylan's character. Do people really believe they can decide for sure who is what based on a mere character introduction and few short scenes. We all thought Ellie to be the kind who is sexually active and has probably had sex with many guys seeing how she was all making out Infront of her mother with a guy she just met. Then comes the revelation that she is a virgin. So just assuming what Dylan is based on the initial days of the game and calling anything new about the character as poorly written or incorrect is not right.
When he stood up for her against the hobos it finally tipped the scale towards Dylan being recognised as a man by her.
It would be the case for any mother, the difference would be a normal mother won't think sexually about this but Sophia's thought are a bit leaning towards that.
There has been gradual progression and no out of nowhere huge event for Dylan. Slowly and steadily things have moved and I just don't understand why most people consider even the smallest if things as a sign of something huge.
They stop thinking like an actual human but more like the characters of the porn game, making a mountain out if molehill, with only how every word could mean that the dev is insinuating sex between two characters.
I am fine with a healthy debate and agree or disagree - it's all good.
This is an erotic novel where incest is part of the story - we just don't know all the specifics yet since this is L&Ps story to tell. Potential storylines include:
between two sisters (Sophia and Patricia)
between mother and daughter (Sophia and Ellie)
between mother and son (Sophia and Dylan)
Saying that no mother looks at her son as a man in real life is not true but it is far less common now - and certainly not acceptable in present day mainstream Western society (at least the thought process that sees the son as not just a man but as a potential sex partner). There were times when it was more common and acceptable (powerful families and dynasties kept things in the family through intermarriage to preserve power and wealth, for example).
Let's set that aside though.
You don't make any argument that incest is not going to happen, but you are trying to use real life societal norms to explain Sophia's thoughts and feelings when she is clearly on a path to some number of incestuous relationships.
Did Sophia get jealous of Amber's attention and affection for Dylan at the end of the chicken fight? YES! (and this is where the Sophia/Dylan path had ended so it makes much more sense for her to Not have those feelings here - since she effectively rejected any incestuous relationship with Dylan by going the boarding school route).
So why not have something similar or showing even more jealousy for the Sophia/Dylan path?
Where are the other bread crumbs that lead up to Hobo fight?
L&P has created a branching story including two Dylan paths and he could have added in, with almost no effort, Sophia's introspection where she starts to see Dylan as a man, ahead of the boarding school decision that continues or ends the Sophia/Dylan path. Sophia's story is Not mainstream real life - so saying that she would not have those thoughts is imposing a mainstream world view on a family well outside the mainstream view of what family means - it is a non sequitur, it does not follow. I recognize it is not what you want given how you view the story but that does not invalidate my stated perspective just because I see it differently.
Sophia could have rejected any thoughts of how hot Dylan's soccer moves were ahead of the boarding school decision, seeing only how he is growing into a man.
Once she decided to keep him in school (rejecting boarding school and continuing with the Sophia/Dylan path), other chances to view Dylan as a man and to see some of what he is doing as 'hot' would not be always be rejected because her thought process would be evolving.
I believe that minimal additional story-telling work by L&P could have laid a better trail of bread crumbs (showing her changing perspective) to the Hobo defense event than it did.
He could have simply used existing renders with added introspection to capture the change in her perspective.
(This is yet another place where L&P could have used the opinion of a trusted advisor, in this case to help refine AWAM's story and improve the Sophia/Dylan story arc.)
I stand by my view that the Hobo defense was too much like a magic switch versus the character evolution we are seeing with other Sophia relationships.