I don’t think he’d do it, but not because of his past. David has always been the one not really wanting to work with Gillian outside of XF because he felt like he had to be protective of what they had and their character. Gillian really wanted to guest in Californication but he never agreed to. So even if there’s no more XF, I feel like he’d never want to do another project with her. At least not on TV as actors. Maybe one day they’ll find a way to collaborate on something different though.