Ok, it took me a while to import the project in the IDE to have a look. I now understand what you mean, and remember our discussion.. indeed it's a slightly different thing than what I had in mind when creating the issue, but they seem strongly related.

For both purposes I need to rethink the role of org.hibernate.cache.spi.CacheKey; it would be excellent to have only one instance for each of internal CacheKey, cache-specific CacheKey(s) and also EntityKey.
I'm not sure how far that's feasible but it's interesting to try...

While I remember us previously discussing on the 2lc implementors wrapping our cache key.. I'm not finding that in the source code now. Would you have a pointer of where these are generated?