I am not a fan of blue cheese either. I remember in the service I had a burger and thought I was putting a dallop of mayo on it. I took a bite and had that mold flavor filling my mouth. Ewwwwwwwww. Anyone ever see that maggot cheese called Casu Marzu? They eat in Italy. They scoop the creamy cheese from the center with crackers digging around the maggots. I wouldn't recommend that as a substitute for blue cheese.
I would think that Feta Cheese would go well with that recipe though.

Casa Marzu Cheese

Nothing in the world could make me eat maggot cheese!
I have a very weak stomach.

What about Gorgonzola? Similar to blue cheese IMO, but better flavor.

...turning this sauce into a rich "mornay" simply by adding parmesan & a grate or 2 of nutmeg would be lovely, janie...