Metadata (tags) in frames
I'd find it very useful if I could use metadata in frames like it's already possible to do in headers / footers.
That would enhance coherence between metadata and what is actually printed.
Currently, the contents of tags filled during score creation are duplicated in the top first frame, but the link with the tag name is lost.
In headers/footers, it's possible to enter $:variables: to be replaced by actual contents.
An option could be to create an edit dialog for frames in which one could enter $:variables: as for headers/footers. Whenever one validate this dialog, the values are parsed and the content actually displayed in the frame reflect the values of the variables.
Furthermore, user-defined tags could be honored as well.
Warning: in this dialog, it's important to still be able to affect a text style for a paragraph (Title, Author, etc.)
pros: The proposition is efficient, simple and consistent with other portions of code
cons: It'll no more be possible to directly edit the content of the frames