Comment 4 for bug 1696771

Hi, that's not exactly how $SNAP_COMMON vs $SNAP_DATA works.

When a snap is upgraded, the content of the current $SNAP_DATA is copied into the new one.
This allows the application to change those files during (or after) the upgrade process, without affecting the old ones (in case of a revert).

On the other hand, $SNAP_COMMON is a single directory, shared by all snap revisions.

So, both directories work for this case, and any change made to those templates would be carried forward when upgrading the snap.