I'm not sure that Desi will have much to do with Al, tbh. Maybe random run-ins at the Manor are a possibility though? Or perhaps if Desi has any missions that he needs AP help with? Seeing as all the fieldwork operatives are now just bumming around at the Manor.
I do have Jos though. Who is a Byrne cousin. So Desi definitely knows him? I imagine if he's friendly with the Byrnes, Jos will definitely be friendly with Desi too. He's pretty close to his cousins. So. I'd be up for threading them some time!