A few months ago u/ikpensco shared a post
of their custom nib grind developed after being unable to find a nib both fine and flexible enough to satisfy.

https://www.reddit.com/r/fountainpens/s/az6WSiwDm7

This has been my rabbit-hole search as well. I pretty much begged them to make me  one I could purchase. And they did. I have had it for just over a week now and it is my *dream* nib! Absolutely my holy grail.

The pen is a Waterman 52v in the Woodgrain colorway, which is a delightful pen in and of itself. Then the grind. 
Ultra fine to a deliciously generous flex. It arrived beautifully packaged, with a sample of Lamy Blue-Black and an entire Midori notebook so I could experience the nib properly.

I’m not nearly the photographer nor calligrapher they are but here are some pics of my scribbles. Below is a transcription of the two-page spread.

“Beautiful ink, beautiful nib, beautiful pen. Dreamy. Perfect for me. It is not a simple writer. There is ease of use. The sensitivity and range benefit from awareness, attention, and intention. 

I love the delicacy and elegance on the page. Pure gossamer lightness and fineness. Range the moment I want presence. Dynamic. And if I relax and let the natural brush effect over the paper determine the weight distribution I am pleased with the natural variation.

Delighted and awestruck. Ink is Sailor Suki Gokoro filled on top of Lamy blue-black residual. Waterman 52v Woodgrain. I really love pre-WWII Watermans. Modern Carenes are lovely too. Fountain pens are amazing tools. 

The fineness of the nib does catch paper fibers easily.  Can also puncture through an unsupported page with shocking ease. The Midori Cotton is even a bit too soft and catches fibers. Regular Midori, Hobonichi Tomoe River, and CD Premium have all been fine. Onionskin is tricky.”

I found my dream nib! IK Custom Point Grind