Custom bar numbering

Your idea

Add the ability to fully customise displayed bar numbers - in particular, to have bar numbers with letters in them.

At the moment, bar number customisation is limited to simply adding or subtracting from the underlying bar number count.

Problem to be solved

In musical theatre scores, it is very common for inserted bars to be given custom bar numbers with letters in - e.g. if two bars were inserted in between bars 41 and 42, they would be labelled 41, 41A, 41B, 42.

There are workarounds, but currently no real way to get this working properly.

Prior art

Apparently Finale could do this (though I haven't used it myself) - https://usermanuals.finalemusic.com/FinaleMac/Content/Finale/Measure_numbers.htm

Additional context

Raised on forums here: https://musescore.org/en/node/367609

Checklist

• This request follows the guidelines for reporting issues
• I have verified that this feature request has not been logged before, by searching the issue tracker for similar requests

The issue names no implementation files, tests, or entry points; begin by locating the existing bar-number customization and reviewing the linked forum discussion. Done means inserted bars can display custom labels such as 41A and 41B while preserving the surrounding numbering.