I always thought I had read somewhere. The possibility to send Dylan to boarding school ends after the third (fourth) assignment. But maybe I was just dreaming it or listening to a rumor.Apparently there will be another solution later on playable day 17. Which will be a difficult solution. So if Sophia does not accept Morello's help, the Aiden storyline continues. If she refuses in between then ofcourse the Dylan route ends.
How I theorize the events will play out is :-
Sophia will do or not do the task.
If she does not, then Dylan is sent to the boarding school as usual.
If she does, then at the end of the task, while she reflects on what she did, she will have the thought of asking Morello for help.
Hence why we have the Morello event as Optional. If she takes his help, Aiden is dealt with plus a scene with Morello.
If she decides not to take the help, then things will stay just as usual.
But this path would be ideal for the Cuckold Route from Dylan. Dylan could take part in some of the events as a watchdog, just to prevent Aiden from taking advantage of the situation again and trying to rape Sophia, but the rest of the event would not be affected. But no matter, actually the starting point of the considerations is always the impossible position in which Dylan finds himself. He is the son, in Liam Sophia has an attractive, experienced man, there is Sam the rock musician, Alyssa the beautiful elf (of course she actually belongs to Old Dog) or Zac her son. It has to be an extreme scenario that brings Sophia and Dylan together over a long period of time. Aiden blackmail would be such a scenario. Dylan would be concerned and jealous at these events, but would have no way or interest to totally sabotage them. In the case of an incident with Sam, for example, this would be a completely different matter.