Critical Cache Management Issues in W3 Total Cache Plugin

In the realm of website performance optimization, two significant issues have come to our attention regarding the functionality of the W3 Total Cache plugin. These concerns have been observed both in controlled test environments and across a spectrum of our websites and customers of our ISP..

1. It appears that W3 Total Cache does not respect the 'Expires header lifetime' value. This is set to 1 year, but the cache is cleared within 24 hours. I have observed this phenomenon both in my test environment and with all our customers. Unless I'm missing something, this looks like a bug. I couldn't find any relevant information about this on the W3 Total Cache forum.

2. When a cache expires, W3 Total Cache adds "_old" to the file name. Then these files should be cleaned by the WordPress cron (pgcache_cleanup), but this does not happen. Even when I run this cron manually, no cleanup is performed. This problem also occurs with other customers of ours, leaving many old cache files behind.