I'm curious as well. Afaik, 32GB has been the documented max for both recent Ryzen Embedded as well as Intel NUC. Having said that, the Intel NUC (6th-8th) Gen can take advantage of 2 x 32GB SO-DIMM and I believe, I may have been the first to at least confirm this publicly [1].

I also recently did the same for an AMD M1000V system which I had shared [2] and will posting a blog post soon with more details on the unit which is similiar to the SimplyNUC Sequoia system.

[1] - https://www.virtuallyghetto.com/2019/03/64gb-memory-on-the-i...

[2] - https://twitter.com/lamw/status/1194851757261611008

Here's the blog post[1] reviewing the ASRock M1000V

[1]- https://www.virtuallyghetto.com/2019/11/hands-on-with-new-am...

there are 2 NUC, I saw it at the most expensive one