This is exactly my use-case for a fossil repo with the built-in forum, with the default provided sorting. Fleeting notes get migrated as needed to Wiki pages (capability for which is also built-in).
Demonstration of default settings: https://fossil-scm.org/forum/forum ("most recent threads" is equivalent to "most recently updated thread")
The Mutopia project is dormant (per admissions and observations from contributors in the project's mailing list), and under current maintainership (or lack thereof) having contributions processed is hit-or-miss[0].
> latex versions of music
Lilypond is not based on (La)TeX, but lilypond-book, a companion utility that processes lilypond files, allows scores (or fragments) to be integrated into LaTeX, DocBook, Texinfo, and HTML documents[1].
(There is a LaTeX package for music typesetting called MusiXTeX[2], which was used by many scores of the former Werner Icking Music Archive, which merged[3] long ago into IMSLP).
Opt-in telemetry, as well as unspecified telemetry while phoning home for license checks. I gather from memory that IDEs based on the IntelliJ platform scour the local network in search for other local network-connected machines running instances of their IDEs - e.g. in order to detect forbidden duplication of licenses. It is not apparently clear what details are(n't) transmitted back to the mothership.
This example requires a finer-grained analysis than the broadly chosen "opt-in" and "opt-out" categories to describe telemetry collection, and I wish for this information initiative to improve in clarity and thoroughness (e.g. does VSCode also scour the local network?).
Addendum: Thanks for asking for clarification. The grandparent comment could've been ambiguous in intent.
Demonstration of default settings: https://fossil-scm.org/forum/forum ("most recent threads" is equivalent to "most recently updated thread")
Docs: https://fossil-scm.org/home/doc/trunk/www/forum.wiki