Here ,
litepseed plugin disabled TTFB 0.667
http://prntscr.com/k21u48
litespeed plugin enable caching OFF
no custom directives TTFB 2.18sec
http://prntscr.com/k21tcg
so on a netweork where I need to use the plugin on 2 out of 10 sites ,
2 will see benefit , 8 will suffer from the plugin not...