Same problem, researched to a dead end. So far, Zline is the only mfg I've found, but they are marketed many ways. They are specific sizes only.

Other than differences in stainless steel color and surface treatment, one would expect so. Do you have a photo of the area of interest?

The dry wallers cut a little far out and that is why I was looking to get a stainless trim kit

Is this something a sheet metal shop could fabricate?

That is a call the drywallers back issue, not spend $300 on stainless trim that will only highlight an error.