I notice that you have made it a default that the string number size is different when entered from the properties panel as an attachment to a note versus the right side panel where the string number is attached above the stem or below the note. Also when several notes are selected and string x is selected in the popup, the larger text is used. I find this inconvenient and potentially misleading: string indications should all be the same size. They communicate the same information whether they are situated near left hand fingering, or stem or notehead side. I realize the counter-argument is going to be that the string indications placed near the left-hand fingering need to be small because they should not take up too much space, but that does not imply that the older string indication numbers or numbers attached to lines need to be bigger. An obvious counter-argument to the larger numbers is that they DO take up important vertical real estate when other symbols must compete for the same space, such as tempi, sul tasto, articulations, etc.
In Engraving Options, you can adjust the scaling factor for string indications:
string indications.pdf (621.1 KB)