It’s true that it isn’t necessarily him defining himself by Endeavor, but he wants to be different than his father. It would not be stupid for him to choose to protect his mental health and avoid his abuser and the exact situation that provoked abuse (being trained by him).He literally had a traumatic flashback in the previous chapter to a training session. That being said, you’re right that it’s certainly possible Horikoshi will head in that direction.
Under the cut for a personal opinion:
I am just really confused as to what Horikoshi is doing with Endeavor and Shouto’s relationship in terms of the writing. I think there’s a definite weakness insofar as the framing goes: Horikoshi clearly (as 192 and the recent flashbacks show) does not want to gloss over or in any way trivialize Shouto’s abuse, which is commendable. I do think he really cares about abuse victims and is appreciating how serious the subject matter is. However, he has also committed at this point to redeeming Endeavor and quite possibly towards some kind of reconciliation between him and Shouto, which is again, not my preference, but fine as well, yet the framing is really swinging wildly about between encouraging the audience to sympathize and then to hate and then to sympathize and then to hate. Like, I would have been a lot more cool with him training with Endeavor post-pro-hero arc when Endeavor’s character was really shown in its most sympathetic light, but then showing us these flashbacks that definitely painted Endeavor as cruel and eugenics-focused really goes against painting sympathy for Endeavor so it comes across as messy. That being said, again, the Todoroki family drama is still my favorite subplot in the entire story, messy or not.