Usually when you want to install a MW drawer in a 30" wide cabinet you get the 30" version - it's the same as the 24" but made to fit in a 30" cabinet with appropriate trim to make it look like it's 30". That's what I have.

I'm curious as to why you are going with Zline. From my research, Zline just puts together the components from Sharp, so there's no real difference between them. Is Zline cheaper? It isn't on AJ Madison (out of 4, it's the 2nd most expensive with 2 Sharp drawers cheaper, one by a lot).