I had an easier experience along these lines. The Lenovo ThinkPad X220's official technical specifications say it only supports 8 GiB of RAM. But many forum posts across the web confirm that people used 2 slots of 8 GiB = 16 GiB with no problem (e.g. https://www.reddit.com/r/thinkpad/comments/6rdra2/does_the_x... ). Sure enough, I tried it and it worked.
