Position chromatic notes in 1/3 note head size instead of 1/2

[Robert Mengual]

Hello everyone,

I am trying to position the notes of my custom music notation as in the screenshot.

I tried using a custom callback for staffLineLayoutFunction. I thought it was going to be enough, but it won't allow decimal numbers.

Does anybody have any idea how I can implement this behaviour? Find attached a Tiny.ly as well.

Robert 

Tiny.ly
Description: Tiny.ly

screenshot.png
Description: screenshot.png