I've heard from a sales POC that the Reserve and Pinnacle OBL access to a "curated collection of residences and hotels" will be through ThirdHome. I would speculate that this will be for Abound ClubPoints and StarOptions booking though it's not clear to me whether it would include exchange fees or be covered with the points/options. What has happened with ThirdHome when they have signed affiliation agreements with resort companies elsewhere is that they no longer allow or restrict the establishment of new individual accounts between owners of that resort system and ThirdHome so you have to go through the resort affiliation agreement. What happened with Hyatt is that they do not allow the establishment of individual accounts for trust-based ownerships (i.e., portfolio points or platinum points) but do allow it for week ownerships. I would equate that to the ability to rent out a week you own but not a reservation you make through a mini-exchange system like Abound or VSN. Some people do that and get away with it, but there is risk involved. On the other hand, when they affiliated with Vidanta, they eliminated the ability to use an individual account separate from the affiliation agreement. I would guess that the affiliation of Marriott Abound and Vistana with ThirdHome would wind up being similar to the Hyatt system affiliation, but only time will tell. If anyone is interested in trying them out, it might be best to establish an account with them sooner rather than later.
I don't use my Marriott, Vistana, or Hyatt ownerships with ThirdHome because the cost per trading currency (keys) is higher than it is in other systems, but have had great exchanges with them, particularly for vacation homes in Europe.