G'day pryrt,

++ Many thanks for this detailed explanation.

"... essentially a for-loop that adds predefined user-specific folders to @INC through unshift @INC, ... commands."

Given your mention of "specific implementation of cPanel", I imagine that it's not impossible for one of those predefined values to be tainted in some implementation(s). On that basis, and even if it's unlikely, it's still worth checking cPanelUserConfig to move from, as I put it, "pretty sure" to "100% certain".

Not posting your cPanelUserConfig.pm was the correct decision. I made much the same choice with not "search[ing] the web for an unofficial copy".

Changing the title, to facilitate searching for cPanelUserConfig here, was also a good move.