Thanks for the heads up. The good news is all machine access to the data will be via functions and views so I can inline the constraint in the right places. In other news, this sucks! I have no idea what it
I could see moving your constraint into a per row trigger.
You'd need to basically replicate the current FK constraint setup but with custom queries...you need the insert/update trigger on the main table and then a insert/update/delete trigger on the referenced table to ensure that actions just rejected if the relevant detail on the main table isn't changed. Then decide whether you need something like "ON UPDATE/DELETE CASCADE" instead of the default 'reject' behavior.
I take it you would need to ensure that these triggers are disabled during dump/restore but am not certain on that point.