Doulos SIL Cipher font uses hyphen-minus to indicate extend duration of the preceding note by an entire quarter note for Jianpu notations. However this looks relatively shorter, which could cause some inconsistencies such as imbalanced line length or some positions shifted.
Many Jianpu notations published in China commonly uses even longer dash for this purpose. See these samples.
https://m.jianpu2.com/jianpu/jianpudaquan/214513.html
https://www.everyonepiano.cn/Piano-1682.html
https://www.everyonepiano.cn/Number-5850.html
I suggest adding figure dash (U+2012) for proper appearance.
Hi Dagouzi. Welcome to the community. Unfortunately, we are not doing any further development on the Doulos SIL Cipher font.
The font does include U+2012, but it doesn’t have all the attachment points that the hyphen has. Could you try using U+2012 and see if it actually renders properly? If it does, then I might be willing to update the keyboard so you can input U+2012.
