Maybe that was a "Kampot by invitation only special". Went in this Friday and it turns out the agent who had called me had slightly misspoken: +1% for USD deposits NOT KHR - and this after we had discussed the details on several occasions already, LOL - typical banking in Cambodia, where the staff make one mistake after another. Why not put things in writing?
I didn't get 11% for a modest new KHR deposit but 10.75% after bargaining hard, which makes me the only unicorn in their system.