New RETS resource classes aren't available to existing connections.

Avid user of DRealty. While I am very familiar with DRealty, I am not familiar with the RETS side (provider side) of things.

Apparently my RETS provider has two different feeds. A standard feed, and an upgraded feed that provides a Visual Tour link (a class with a link field to an automated media tour from http://www.visualtour.com/ for each property).

This issue comes into play when a realtor, who currently does not have the Visual Tours class in his/her feed, decides to upgrade their RETS feed in order to get the VTour class. If I initially create the DRealty connection, import the classes, and establish all my field associations using the RETS feed that does not contain the Visual Tours class, then I cannot simply gain access to the class under the same DRealty connection.

If I do an export of the DREALTY connection with the Visual Tours class, then do a diff compared to a DREALTY connection without the Visual Tours class I see this addition:

,"vtour_link":{"systemname":"vtour_link","standardname":"vtour_link","longname":"Visual Tour Link","datatype":"Character","max_length":"9999","field_precision":"0","interpretation":"","lookupname":"","class":"ResidentialProperty","rets_returned":"0","lastupdate":"1417814623","resource":"Property"},

I've tried exporting the NON-Visual Tours DRealty connection and editing, and reimporting. That breaks something in the bowels of DRealty, because it no longer performs a proper rets-import.

Any hints on how I can add this new class without breaking my DRealty Connection?