- Simplify caching channel layer to only have a single cache.
 - Add error message but don't fail if duplicate aliases found during aliasPrefix lookup
 - Simplify channels persistence by removing caching from processing (but not from front end)
Ensure channel caching only performed for front-end
Change channel cache to be BackgroundComputingValue instead of LoadingCache
Log error if duplicate alias found on channels, rather than throwing error.
It helps if actually start/stop the BCV...