Agree with talking to the pen maker, to what nib he suggests.
I would assume the modern Pelikan nib is often butter smooth. They won't be cheap, but a good pen maker can make you a screw in nib section. The problem with nibs that are ground to be butter smooth, is sometimes they are smoothed that little bit too much and have developed baby bottom.
I only have one modern MB and it is butter smooth...
Oddly I like nibs with a bit of give to them....so they really don't get as much use as they could.
What Ron says here, I've read from knife makers............practice makes the master. That and a lot of pride.
""""On several occasions I have gone back to visit a nib that I worked on several years before, and have been surprised that I was satisfied with the work at the time. This is one area where experience really does count.
It’s unlikely that I will use the same techniques today that I used even a year ago. Repair/nib guys are constantly growing and evolving. If we’re not, we’re dead. If I were to suggest just one key to learning how to do good nib work it is to observe…. the shape of the nib, the feel of the nib, and what subtle thing you did that made the difference and how you got there."""
I think experience would help you get a much better custom made pen...which for my wallet is not cheap, when you don't know what you want....what you need.......just the cachet my bespoke pen .......and let me tell you, many change radically their opinions of pens in a year or two's time.
Those who insisted in heavy metal pens, develop a liking for a light and nimble plastic pen. Those who want a nail nib learn to like a regular flex.
It's even been chiseled into stone, that right after the last full eclipse of the sun, someone who used only EEF Japanese pens, started using a Lamy B......Mythbusters are working on that.
I came in, went wide....ended up with a lot of F's and now like M's.
What width, what flex of nib do you want on your pen..............how can you tell?
What inks do you use....what papers do you have? You do need to think about that, when you decide what you want the nib to do.
What are the secrets of the Classic pens...........who can be smoothed to butter smooth, if not smooth enough for you and lots cheaper..............I don't know what you custom pen will cost....and how custom you want...........but think if you chase down 4-5 of the classic used pens, you would have a much better idea what you want, need if you still have I need a custom pen itch.