[itsme]

It is required to store the MSCZ files in the same directory as the respective PDF to have relative links that work both on Android and Win10.

I also work a lot with linked MSCZ files.
I manage the files myself and synchronize the folder structure with my scores independent of MSP. For Win10 the MSP folder where the score files are stored is a subfolder of my GoogleDrive. So googleDrive takes care to keep all my Win10 devices in sync. To sync the MSP folder to my Android devices I use the app Folder Sync. The folder structure is identical on all devices, all file paths are relative paths, relative to the MSP folder. Thus I can just copy mobilesheets.db between my devices, both Android and Win10.

Anyway it might be a good idea to include files of file types that are not directly supported by MSP into some MSP mechanisms like e.g. sync or backup. In that case I could imagine a setting, where users can specify which file types should be handled. Beyond MSCZ e.g. ABC or HTML (for iRealPro) could make sense.