Do I
1) overide all Enterprise/CustomerSegment
then slot in the classes I need to add my own conditions and classes for models to build the DB queries
2) 1) seems bulky, how would I just add my new condition classes into a local folder?
The solution is to override only the models, and leave the block, controller using Enterprise_CustomerSegment module.
These files would be required to update the CustomerSegment module to add a standing order report:
CustomModule/CustomerSegment/etc/config.xml
(with all the model 's)
CustomModule/CustomerSegment/Model/Condition/Combine/Abstract.php
(this may not need to be overridden)
CustomModule/CustomerSegment/Model/Segment/Condition/Combine/Root.php
CustomModule/CustomerSegment/Model/Segment/Condition/Standingorder/Frequency.php
CustomModule/CustomerSegment/Model/Segment/Condition/Combine.php
CustomModule/CustomerSegment/Model/Segment/Condition/Standingorder.php
CustomModule/CustomerSegment/Model/Segment.php
(this may not need to be overridden)