It depends upon the size of the radius between the sink flange and the side of the sink. Fireclay and cast iron usually have a larger radius. The reveal may start where the radius ends on the flange.

These cast iron reveals are larger, but were dictated by the previous sink cutout.

I added photos and sink width is 30"

Joseph Corlett, if you happen to take a look today, Sunday, I will feel lucky! I added photos. I am thinking that 3/8" will look nice, that is half of the width of the sink lip. Is that still a "slight reveal." Or too big? I want to consider leaving space for the caulking. I appreciate your generosity with folks on this site.

EDIT: I just read that I need at least half an inch for the countertop contact, so I think 1/4 inch is the maximum positive reveal for this sink lip that is 3/4" wide. Since there is a curve in the lip, or I believe that is called a radius, I could add 1/8 inch of horizontal ledge to the 1/8 inch of curve. Or, I could add 1/4 inch to the curve for a bigger reveal. Any words of wisdom are appreciated.

Joseph Corlett, sounds good and thank you for the caulking tip.