The knowledge base does not contain a direct answer about moving an installed Synology package itself to another volume.
What it does contain is:
- When installing a package, DSM lets you choose a destination volume if multiple volumes exist, but that is for installation, not moving an already installed package [1].
- For data, you can move shared folders between volumes in Control Panel > Shared Folder by editing the folder’s Location and saving the change [8].
- You can also use File Station to copy or move selected files and folders to another volume [8].
- For some packages, data may be stored in package-related directories such as var, tmp, home, or target inside the package filesystem hierarchy [2], but the fragment does not provide a supported procedure for relocating an installed package by moving those directories.
- The only package management commands shown are synopkg start|stop, synopkg status, synopkg uninstall, synopkg checkupdate, synopkg upgradeall, and synopkg install from a .spk file [6].
So, based on the provided sources, I can confirm how to move shared-folder data, but I cannot confirm a supported method to move an already installed package to a different volume.
Sources used: [1], [2], [6], [8]