Some headcannon type things:
I’m gonna say that Gen 2 synths have hooves that can unfurl into fingers, but form fists when in a hoof shape for running and walking ect. The fingers are useful for working unicorn devices, without having to recreate unicorn magic
His skeletal hoof/hand his not as stable to stand on as his undamaged one. Because of this, when ever he is standing still he’ll probably be fiddling or smoking to avoid leaning on his bad hoof. Think idle animation
All sythns have the Insitute branding in the place of a cutie mark, I’d like to imagine that Ellie or the Soul Survivor painted the Valentine Detective Agency logo onto his flank in an attempt to cover the branding
Unrelated to Valentine but, I’d like to think that Gen 3 sythns that escape are ones that earn their own cutie mark