Does PP work with Varnish or Litespeed cache?
 

As the title says.
See: https://www.vbulletin.com/forum/entr...itespeed-Cache
Speed up vBulletin sites through LiteSpeed Built-in Cache « LiteSpeed Blog

Any product plugin for vbulletin would have no interaction with our software.

There is no specific modifications that I am aware of currently where our software would interact with either of the cache's listed. The only cache we use is of our category cache index thing to generate index content. The majority of actions within our program are performed when generated like viewing a photo etc.