I'm not following the question. We just built a larger walk in shower and didn't use any bullnose yet works best if the tile is through on through and rectified vs. not rectified. Through on through meaning the tile pieces are all one solid piece when you look at it from the side of the tile. Some tile will have color on top of the tile itself with the majority of the tile under the decorative top a different color which would not look ok at all.

Schluter makes all kinds of trim for tile

metal trim yes we used it in some areas our whole shower is Schluter system a great product.

Thanks. I was thinking I should tile the entire front wall of the shower....so instead of the 3" bullnose frame the entire wall would be 12x24 tile like the shower interior.

But maybe people are doing the metal edge. My sister-in-law did that in a contemporary laundryroom. I have never seen it on a shower.

I used 12x24 and no bullnose and no metal. The tile was complete through on through though vs my floor tile was gray for about 4mm then the rest was some strange color that the gray sat on top of. My shower turned out just fine and looks finished not in need of bullnose IMO that is. I can shoot a photo if you need the bathroom is still not done. Can't do it until tonight though.