I’ve been on a voluntary 2 week long chicken breakdown binge, touching up every time to find the answer to this exact question.
Synthetic, 1k seems fine for me. Maybe it ends up a bit higher because Naniwa, but anything past 3k I notice a drop off 2-3 chickens in. 5k gets too slippery. I think if the skills are up for it, go as coarse as you can provided you are still meeting minimum sharpness requirements. 400 grit is my minimum.
Right now I’ve landed on iyoto somewhere between 500-1k grit but seriously scratchy, finished on binsui with a finer nagura. Just stropping on the finisher. Huge teeth for skin and those membrane-y bits, keen enough to slide through flesh.
My honesuki is white #2 tho, it tends to get easily over refined, more so than blue super or CCK carbon. This is mostly my reasoning for leaning so far towards coarse vs fine.