Is Amlogic actually upstreaming any of their newer devices? Or are they going the Realtek route?
Amlogic recently started upstreaming support for S805X2 which is one of their latest budget chips, but it's a cut-down version of S905X4 so in theory that should be useful - they are still making the decision about whether to upstream S905X4 too, but the differences shouldn't be too significant so I hope they do. Regarless, it will be a slow process as their downstream code style is often old/outdated and overal quality is low so it takes many iterations of patches to raise standards to the point where the kernel maintainers will accept things. I'm also expecting them to focus on support for the core board systems only and make no attempt to upstream the media parts. That's a good/bad thing; it's it's the thing we need most, but their downstream drivers are extremely complicated with lots of features and the lack of anything upstream creates the opportunity to apply the "less is more" principle and implement only the capbilities we actually need. Anyway, it's early days and I don't expect to boot LE images on latest generation hardware anytime soon.
but most Matrix add-ons will probably work fine. You can install Greek under Kodi settings > Interface > Regional > Language.