There is still a lot that can be done with that.
Without giving away too much of my intentions in my own game (I hope...), here are a few ways you can make the blackmail side-path matter to the rest of the game (even to the old guys you like):
1) It can serv as a major corruption path for Sophia, that will make her act very differently towards everyone else, especially her son.
2) It will give us more opportunities to see her fucked and abused, with her being very submissive.
3) It can be used to break her spirit a bit and be more needy of a knight in shiny armor of our choice.
There are a couple more ways in which the blackmail route can influence everything else, but I don't want to spoil things for my own players here, so I think I'll stop.
This is an admirable state of mind, and I wish more would adhere to it...