Both engineered by Chris Dugan as well, didn't mention the trilogy because I didn't want to start that debate haha (I actually love the sound of those records other than some weird vocal editing). Trilogy was mixed by CLA as well.
For FOAM I'm not sure how much Dugan was involved after pre-production, I know I heard in an interview with Butch Walker that the title track was using recordings from the band's rough demo done at Otis by Dugan but I'd imagine he was along for the recordings of other songs as well as he's credited as engineer. Maybe not though as I do think sonically the title track wins over everything else on that record. Obviously very different production overall on FOAM though as a result of Walker and that one was mixed by Tchad Blake which I don't personally think was a great fit for GD - but again, hard to tell considering the production style, would be curious to hear a more traditional Green Day sound mixed by him.