FWIW, I'm multi-affiliated having multiple timeshares and, thus, relationships with RCI, II, SFX, GPX, DAE, etc. I've been timesharing since mid-2000 and have traded into
DVC multiple times: BWV (studio, 1BR, 2BR), SSR (GV, 1BR) and Vero (1BR). We enjoyed two weeks at SSR last summer via RCI (July & Sept).
Yes, DVC properties are available for booking through RCI as both exchange and rental weeks. Inventory is very limited, both by resort selection and dates, and the exchange requirements are high. If your timeshare would trade in RCI Weeks, expect to spend 35 TPU (RCI's Trade Power Units) or more plus exchange fee for a 1BR at SSR for one week. If your timeshare trades in RCI Points, expect to spend 55k - 85k points plus exchange fee. If your timeshare has its own points-based exchange grid, expect to trade out at the highest point level for any given category (resort quality level + unit size +season).
Guests trading into DVC through RCI will pay double the normal exchange fee. You will first pay a fee to RCI for the exchange and, on check-in, you will pay an additional ~$190 to DVC.
Again, inventory is quite limited. Expect "1BR at SSR" as the most common DVC offering. Lately, it seems only resorts with
special RCI affiliation are seeing 2BR units. (Welk resort owners have been spotting 2BR units ... but I haven't heard of others? I have no idea on the ingredients of the 'special' relationship.) There have been a few recent sightings reported of AKV and OKW in addition to SSR. Do use an "Open Search" (RCI's waitlist feature) and do manual searches at different times of day. When inventory shows up it is, most often, quickly gobbled up.
Good luck!