Unfortunately covid killed off the Poker Room which made harvesting yellows a costly PITA at table games. I finally completed a rack for my personal collection a couple years ago & haven't been back since.
The pic below is from my peak harvesting days circa 2017-19. Wish I hadn't sold em all but I just assumed I could always get more from the poker room... uhhh oops.
These Cache Creek chips do exist out there in the wild, you just gotta find a seller & be prepared for some sticker shock. GLWSearch!!