How will that work? If we measure the widest digit then when the thinnest digit is present it will be off again ;-)
Hum, indeed… another solution that has been on my mind for ages and I've seen implemented in other apps "lately" would be changing plaintext to individual widgets, and this way we could easily also make it interactive (to change mode, file type, got to line, etc.). But well, somebody has to do it, as you'd say 🙂