users shouldn't ever have to manually delete files from the picture cache folder, rather it should be managed by sonar to keep the folder contents within the size (and other vars?) defined in preferences :-)
maybe there's even room for other improvements nobody's thought of yet :-)

+1.
 
Currently SONAR does not even warn if pic cache folder has grown over the set limit.
I have made 3rd party workaround; in Duckbar (www.sonarmods.com) there is an easy to access "Clear Cache" button which deletes all picture cache files older than a week. Duckbar also warns if cache is getting full.
 
SONAR should delete old cache files automatically in the background, silently.
 

Definitely up for artificially intelligent ('AI') picture cache, may be the first step forward for the rise of the machines.