I think no matter whether you believe B & E are grifting, were or are aware of their parents wrong doing or not it would be sensible for them to give up their titles now.
It would give a clear definition between them and the gutter level of their parent’s behaviour and if I was their PR person this would be my best advice.
Whether they make any comment on their parents is a separate issue.
Personally I think the renouncing of titles would be enough and whatever type of relationship they then have with Andrew and Sarah can be a private issue.
I really think that giving up their titles would be helpful to them both in their future lives and would be a respectful gesture to anyone who has suffered at their father’s hands.
It does not mean they are personally guilty, it means they recognise the horror of it all.
I would also add that if they accept the truth of their father’s behaviour in particular then why would they want the titles he insisted upon?
A previous poster made reference to growing up with a sex offender so I will explain that my father was an abuser of women and children and there is nothing I have ever wanted from him and I have always gone out of my way to distance myself from any association, any tiny degree of resemblance, anything at all such is my disgust for him.
I suppose it comes down to whether Eugenie and Beatrice prefer to live in denial and keep the material comfort of being princesses or they want to face the truth however awful.