I do wonder if that Mac Mini from 2011 I have but haven't used in a long time also secretly supports 16 GB. I upgraded it to 8 GB ages ago and the docs said that's as far as it goes.
Funny timing: I just upgraded a 2011 Mac Mini from 4GB to 16GB yesterday, and it works just fine. After searching around, I found a site (can't remember the name) where they specifically call out that the actual amount of RAM that various Macs support, regardless of what Apple's official specs say.
(Had to crack it open because the old spinning-rust hard drive was starting to go bad, so I replaced it with an SSD, and figured I should upgrade the RAM while I had it open. I have Linux installed on it, and it's a nice media server box, running Jellyfin and a few other things. Only downside is that its support for HW video decode/encode is kinda limited -- no h265 -- due to its age.)
I use my 2011 Mac Mini with 16GB. Been running it that way nearly since the day I bought it. It’s on its 3rd HD, a 120GB SSD. Wikipedia article mentioned it would work with 16GB so I upgraded it as soon as I could.
