Wow, I wish I could give this post more likes! You really went above and beyond to prove your point, and I'm so glad you've been vindicated!
BB&B $100 eGCs often sell for $90 on eBay/PPDG, which earns 3x UR when paying with CIP and 5x UR when paying with CIC/Ink+ credit cards, so there's a deal to be had if you can trade it in for a Disney GC. (But for the same discount, BBY eGCs seem to be more of a sure thing.)
I've been looking into the BB&B situation, and it seems a fair amount of people who comment on SD, Reddit, DoC, FM know that BB&B allows GC>GC but keep it on the down low. With all the reports in just this thread about uninformed cashiers shutting us down, I'm scratching my head how these people even get their transactions through. It almost doesn't seem worth the hassle. One tip I read was to use the eGC to order a physical BB&B GC (free shipping) on the website and then use the physical GC in stores. I haven't tried this personally, but I suppose it could work. It would add a few days to the flip, but I wonder if it would make the in-store transaction easier if you can just swipe the physical card at the terminal.
@Eighty8Keys, were you using an eGC?