Decision Manager comes with one only that it leaves EXPORT stuff out because it is intended for import schemes only. But it does the worst part which is exporting conditions. I've used it effectively together with some table dumps.

I bet there are some customizations out there but I always thought it would be nice to have it standard.

In LN, the Exchange Package is renamed from TU to DA. There are new sessions to import and export Exchange Schemes in XML format. I think they can also be integrated with PMC as Additional Files.

Well, maybe it has already been solved: I used to generate exchange scheme's to export and/or import exchange schemes, including multiline text for the conditions. Within 10 minutes, the exchange scheme at another site/customer was ready.