For Philo, the Logos did not become human; it remained a distant mediator, a non-personal force that facilitated the interaction between God and the material world.
That is an interesting topic. Philo seemingly allows for this as he does say:
Logos that is called God... For no name belongs rightly to the Absolute, who
is of a nature to exist simply, not to be described. There
is an old legend that the deity at different times visits
different cities in human form,
is an old legend that the deity at different times visits
different cities in human form, seeking out cases of unright-
eousness and lawlessness. Perhaps it is not true, but even
so it is profitable and expedient that it should be current.
And Scripture, though it employs more reverent conceptions
of the Absolute, does at the same time liken God to man,
speaking of his face, voice, anger, and so forth, for the profit
of the learner. Some are so dull that they cannot conceive
of God at all without a body
of God at all without a body.
It seems Philo is suggesting that the Logos (the deity) may have actually appeared as flesh, but he was not sure of the literalness of the legends. What seems clear is that in at least some discussions he did personify the Logos to a high degree.
What is the man who was created? And how is that man distinguished who was made after the image of God? (#Ge 2:7). This man was created as perceptible to the senses, and in the similitude of a Being appreciable only by the intellect; but he who in respect of his form is intellectual and incorporeal, is the similitude of the archetypal model as to appearance, and he is the form of the principal character; but this is the word of God, the first beginning of all things, the original species or the archetypal idea, the first measure of the universe. ...
Notice he describes this 'word of God' as a incorporeal "being". I'm not sure just how literally he conceived of it (or more importantly his readers) but then as I said all of this is imagery of invisible stuff, (he like many understood the Primeval History as allegory) so where does metaphor start and end.
It seems relevant that within the larger Neoplatonic concept of Logos as a bridge between spirit and corporeal, we do find traditions that describe the Logos figure as sharing in the corporeal including having flesh. (Osiris/Dionysus).
So, while Philo unsurprisingly doesn't expressly say his Logos took on flesh he does see in Moses and Aaron and other human characters the 'internal Logos' and 'utterance Logos' embodied. He also leaves open the possibility that legends that say Logos/God did take human from may have happened.
Also parallel the Christ/Logos of Paul et.al. is the role as high priest.
For there are, it would seem, two temples of God — the
one, this world in which God's firstborn, the divine Logos,
is highpriest ; and the other the rational soul, whereof the
true man is priest, whose material image is he who performs
the ancestral prayers and sacrifices,
the ancestral prayers and sacrifices, who is commanded to
put on the aforesaid coat (of finest linen), the counterpart of the whole
heaven, that the world may join with man and man with
the universe in the rite.
So, here we have Philo describing Logos as a High Priest whose rite affects the world. Of course, the writer of John or Paul had something new to add to the story. The propitiatory death (sacrifice) of the Logos/Christ. Philo (or his Alexandrian school) didn't come up with that one though I believe he, being fond of allegory, could have appreciated it. Paul, remember, claimed to have drawn his Christ from scripture typology in Philonic style.
Regarding your comment that Christianity especially since Nicaea have a distinct formulation of God. That is true. Yet there were steps along the way. Origen as you know mentions Philo as one of his predecessors and shared many notions of freewill and the divine. They later declared his ideas heretical. It is also interesting that the Nicene Creed includes the words,:
“God from God, Light from Light, True God from true God, begotten not made, one in being with the Father. Through him all things were made. For us and for our salvation he came down from heaven.”
Which appears to be quoting Philo.
In the same manner God, being his own light, is perceived by himself alone, nothing and no other being co-operating with or assisting him, a being at all able to contribute to pure comprehension of his existence; But these men have arrived at the real truth, who form their ideas of God from God, of light from light.”(Praem. 45-46)