Mark,
Had a similar thought where the stored process metadata object itself may not be able to be change managed, but the underlying code is save as a *.sas file which me manage via a DI User Code node (similar to how we manage macros).
This is the first time I've encountered a site which wants to change manage "everything", and since we're using DI projects to change manage the bulk of the ETL work, they've asked if it can be extended further. Didn't realise til now that you COULDN'T change manage stored processes - seems an odd gap.
Regards,
Andrew.