I've already explained my point of view that when talking about intent and impact, intent takes precedence over impact because if the intent is to inflict pain and suffering, be it emotional or physical, the impact on the recipient's mental well being will be worse.
Your premise comes across to me that any issues in the relationship between and AC and his/her parent(s) stem from childhood and although this of course is sometimes the case, it isn't always.
From the link you provided it states it is also important for the hurt party to extend forgiveness where possible especially when the intent was not malicious. This not only supports my point of view of the importance of intent, but also the necessity for the 'injured party' which for the purpose of this discussion is the AC, to understand and accept the fallibility of their parent(s).
Also from the link is pause before responding take a moment to reflect how your words or actions might be received. Good advice for parents and their adult children.
Without specific examples of EAC's experiences of trying to engage with their parents about how certain events in their childhood made them feel that their emotional needs were not met, this link is just as applicable to all relationships.
IMO you've tried to make impact and intent specific to parent/child relationships with the onus on parents, and the link you've provided simply isn't specific enough to do so.