I have an EE 1.12 Magento install with 2 websites. We would like the increment_id of orders to be shared between the two stores. e.g order 1 through store A will be 100000001 and order 2 through store B will be 100000002, rather than the default functionality where the two orders will be 100000001 and 200000001 respectively. The same for invoice, shipment and creditmemo.
After doing some research I have been able to implement this by changing some entity configuration in the database. Specifically setting eav_entity_type.increment_per_store to 0 for each of these entities, and then setting eav_entity_store.store_id to 0 for the default store so it applies to all stores.
I have tested this on a clean install and it seems to work ok, however this doesn't seem to be officially documented anywhere as a feature so I am a little hesitant to use this method. My questions, a) has anyone implemented this successfully in production sites? and b) are there any hidden gotchas that might show up by changing these settings around.