I would like snap merging to be added to the snap store. This would simply delete the snap to be merged and alias it to the other snap.
Snap merging would be (very) useful when people double up snaps, or someone creates an unofficial snap, then later an official snap is released. The unofficial snap could simply be merged into the official snap, and then only one snap would have to be maintained.
There would also have to be support for an intermediate script, for example when the two snaps have data directories in different places.
This has come up several times and is related to renames (see below). Both features require a design for snapd handling to define the semantics and interaction with the store. The store end of things is trivial in comparison.