This feature is now available in the public beta of Gospel Library for Windows 10. Keep in mind that this beta is a genuine beta, and has a number of bugs, both known and unknown. You can learn more about the beta at the link below:
https://tech.lds.org/forum/viewtopic.php?p=162902#p162902
Because this feature hasn’t yet made it to the release version of the application, we’ll keep the suggestion open as “started” until it is available for everyone.
Changes to the annotations web service mean this was able to be implemented for v4 (the upcoming Windows 10 version) of the app.