SubprocessContext Parameter
There is one parameter for the SubprocessContext of the SubprocessPool, com.arbortext.e3.initialScript:
Parameter name="com.arbortext.e3.initialScript" value="filepath"
initialScript allows you to set environment variables in an ACL script before loading information from the custom directory. For example, you could have different custom directories for each Sub-process pool because initialScript is processed before the custom directory.
You could use the ACL file specified by initialScript to set something like:
main::ENV['APTCUSTOM']='D:\special_custom'