Below you see a page with an embedded image and some matrices converted by make4ht.
As a first test I built also a tiny test ebook with tex4ebook. You can download this ebook here and open it in Linux with document viewers like Xreader or Atril in Linuxmint Mate or Debian. Then everything is properly displayed. In Windows you can install Calibre as reader, which displays the ebook well. Of course, with a notebook or PC a pdf version as document format is a useful alternative to the ebook format. Currently I did not yet find a suitable EPUB reader for Android devices, which shows the matrices and brackets properly. I did not test my example with any Apple devices.
