Advanced Time Signature

Your idea

Being able to write some advanced time signature in a simple way. For the moment, all we can do is to have text / text without being much more.

In the following case, I was trying to write a 6/8 alternating with a 3/4, but in a shortcut way.
Here is what I had

And what I was trying to obtain was more this kind of layout

Problem to be solved

Time signature creation are limited to text / text (6+6 / 8). It would be great to extend it as to have multiple time signature in one : 6/8 + 3/4.

Subsequent problem to solve (which is one as whole too) : multi-bar beam groups customization. For the moment, we can have a beam group layout per time signature, which repeats itself on every single bar (i.e. is the same for every bar on which the time signature applied).
For example, I had to write a 7/8 which was 3+2+2 / 8 followed by a 2+2+3 / 8. My "fix" was to have two 7/8 signature on my palette, one for each beam group layout (and hiding all but the first one).

Prior art

No response

Additional context

No response

The issue names no files or tests. Start by locating the time-signature creation flow and the beam-group layout logic, then trace how signatures are applied across bars. Done means supporting alternating composite signatures such as 6/8 + 3/4 and different beam-group layouts for successive bars.