He said BCV and VGF are the two hardest ones to get but I could go on the waitlist for either/both/whatever resorts I wanted.
Those, along with VGC, seem to be the hardest. If it is what you really want, I would get on any waitlist that there is, and then call back every week or so to see where you stand. 18 months cannot be a specific number because they do not know how many contracts they will be getting via ROFR. If you are only looking for 25 points, your odds are better, too, because ROFR'd contracts of 40 points would not benefit people who are looking for 100 points at one time or something along those lines.
That being said, it could still be a very long wait. They have to wait for the right contract to come along, and you have to be the next in line. VGF is a very small
DVC resort, so you are not working with a great number of contracts, especially for a small UY.
If you are looking to add on just for the direct sales benefits, I would probably play it safe and add on at another resort you are interested in instead of gambling that your VGF points will be available both while they are at their current price and while the minimum add-on is 25 points.
You are not limited CCV or Poly to add on at if you are interested in other resorts, just know that there may be a waitlist of some size anywhere else you are interested in.