Heya neighbor! Just FYI, I placed a request for an add-on with my most excellent guide back in February, and she came up with them within a month. I put in a request for 65 BWV points, Feb UY. By the time they came in, we of course wanted more, but the rest of whatever contract they got thru ROFR had already been disbursed, so we settled for 65 more.
Now, I called my guide again in May, and at that time she had a little over 100 BWV points (w/Feb UY) that she could have sold me. Sadly we passed then, but I get the impression that with a good guide, your add-on will come thru at some point.
My advice for a purchase strategy given yor facts: tell your guide that you'd be interested in any amount up-to say 100 (or 50) points, and call back and bug her/ him every week.
Oh, and for simplicity's sake, stick with one home resort, and maximize your reservations power there. Who knows, some time you might even spring for one of those glorious GVs.
Good luck!