For uProduce the registry key is the same, but the path is different:
HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\XMPie\XMPie uProduce Server Object\1.00.000\
In the case of PersonalEffect Enterprise where there are one or more production servers, the key needs to be set on all uProduce servers where print production is occurring.
If better access to this feature is important or helpful for you, you should log a feature request to boost the priority of this with the product manager.
Some purists would probably say that using a whole PDF layout as a graphic asset is sloppy work and that the layout should really be managed in InDesign. - I mean that the asset mechanism was designed to bring an image into a layout, not to bring in a layout to simply overlay dynamic objects. In most cases it is easy enough to ask the client for the original source of the PDF, or to convert or recreate the PDF to InDesign. Yes, it takes time and effort, but the whole job is more efficient, easier to update and maintain.
I do understand the real business pressures that force designers to take this short cut - and it does work well enough. Maybe it was the same business pressures that forced XMPie's R&D team to implement a registry hack instead of a full blown feature?