CSS3 and Math compatibility

[simurq]

Good evening!

Sorry if it's been asked before but I'm new and I couldn't yet delve into the forum space. So, please do with this topic what you believe is necessary...

Anyway, AFAIU from what I read here and there, Pocketbook is one of the most praised readers in the market today. I've got Kindle Paperwhite and think to switch to Pocketbook or Onyx. I'm also planning to design cross-platform ebooks particularly focusing on reflowability including some technical content like formulas. But before that, I'd like to know to what extent both models (sorry, I'm asking about Onyx here too not to spam the other thread with the same request) or any other models that fit the below criteria:

1. support as many CSS3 features as possible (like media queries);
2. support embedding math/physics formulas or at least SVG images.

Being private, e-reader manufacturers are apparently not willing to share much info outside, so I think this forum is the best platform to read/discuss more about the ongoing development...

Thanks!